This document provides information about heating and air conditioning systems. It discusses the components and operation of both manual and automatic temperature control systems. It covers the heater core, evaporator, condenser, compressor, refrigerant lines, and sensors. It provides warnings and cautions for safely servicing the A/C system. Refrigerant R-134a is used, which requires special equipment, hoses, and oil compared to R-12.

1. ZJ HEATING AND AIR CONDITIONING 24 - 1
HEATING AND AIR CONDITIONING
CONTENTS
page page
COMPONENT SERVICE . . . . . . . . . . . . . . . . . . . 31 REFRIGERANT SERVICE AND PERFORMANCE
COMPRESSOR SERVICE . . . . . . . . . . . . . . . . . . 27 TEST . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7
GENERAL INFORMATION . . . . . . . . . . . . . . . . . . 1 TORQUE SPECIFICATIONS . . . . . . . . . . . . . . . . 44
HEATER AND AIR CONDITIONING TEST WARNINGS, CAUTIONS AND SERVICE
PROCEDURES . . . . . . . . . . . . . . . . . . . . . . . . . 13 PRECAUTIONS . . . . . . . . . . . . . . . . . . . . . . . . . 5
GENERAL INFORMATION
This Group deals with manual and automatic tem-
perature control (ATC) systems.
For proper operation of the instrument panel con-
trols (Fig. 1), refer to the Owner’s Manual provided
with the vehicle.
Fig. 2 Blend-Air Heater and A/C System
(heated, non-heated or cooled air) is controlled by the
temperature knob on the instrument panel. Direction
of the air is controlled by the mode knob on the in-
strument panel.
The blower switch and resistor block controls the
speed of the blower motor. This in turn controls the
volume of air flow through the system.
Fig. 1 Manual A/C and ATC Controls SIDE WINDOW DEMISTERS
The side window demisters direct air from the
All vehicles are equipped with a Heater A/C unit
Heater A/C assembly. The outlets are located on the
housing assembly (Fig. 2).
top left and right edges of the door panels. The De-
HEATER SYSTEM misters operate when the mode selector is on
All models use a Blend-Air type heater. Outside air FLOOR, BI-LEVEL, FLOOR/DEFROST or DE-
enters the through the cowl opening. The air then FROST mode.
passes through the plenum chamber, evaporator and
then the heater core. Air intake openings must be AIR CONDITIONING SYSTEM
kept free of obstructions, so sufficient volume of air The A/C compressor increases the pressure and
can enter the system. A temperature control door in temperature of the refrigerant. The heated refriger-
the housing directs incoming air through and or ant vapor is pumped into the condenser where it
around the heater core. The amount of blend air cools by giving off heat to air passing over the con-

2. 24 - 2 HEATING AND AIR CONDITIONING ZJ
denser fins. As the refrigerant cools in the condenser,
it condenses into a liquid. Still under high pressure,
the liquid refrigerant passes into the fixed orifice
tube. The fixed orifice tube meters the flow of refrig-
erant into the evaporator coil. A low pressure is
maintained by the suction side of the compressor. As
refrigerant enters the evaporator, it begins to boil by
absorbing heat from the air passing over the evapo-
rator coil. Having given up its heat to boil the refrig-
erant, the air is cooled and passes into the passenger
compartment of the vehicle. From the evaporator the
vaporized refrigerant enters the accumulator which
separates the liquid from the vapor. The vapor and
oil are drawn back into the compressor to repeat the
cycle.
Ambient air intake can be shut off by closing the
recirculating air door. This will cool the air that is al-
ready inside the vehicle. This is done by turning the
temperature control knob to the RECIRC position.
On ATC systems a RECIRC button on the control is
used. Depressing the A/C button will allow refriger-
ant to flow through the evaporator. This cools and
dries the plenum air before it is directed through or
around the heater core.
The ATC system lets the operator adjust the tem-
perature of the passenger compartment. A computer
built into the control panel, regulates the tempera-
ture, air flow direction and blower speed. The opera- Fig. 3 Accumulator
tor may select an AUTO mode feature in which the AIR CONDITIONING CYCLING SWITCH: The
computer selects the blower speed and air flow direc- switch is mounted on top of the accumulator (Fig. 3).
tion. Refer to the Owner’s Manual for proper opera- The switch is wired in series with compressor clutch.
tion. The switch contacts open and close turning on an off
the compressor clutch. This regulates the system
A/C COMPONENTS pressure. Low ambient temperatures, below approxi-
ACCUMULATOR: The Accumulator is mounted in
mately -1°C (30°F) will also open the switch contacts.
the engine compartment on the right side of the ve-
This is due to the pressure/temperature relationship
hicle. The inlet tube of the accumulator attaches di-
of the refrigerant in the system.
rectly to the evaporator core outlet tube. Refrigerant
enters the accumulator canister through the inlet CONDENSER: The condenser is located in front of
tube. The liquid oil-laden refrigerant falls to the bot- the engine radiator (Fig.4, 5). Its function is to cool
tom of the canister which acts as a separator. A des- the hot high pressure refrigerant gas. This causes it
iccant bag mounted in the accumulator absorbs to condense into high pressure liquid refrigerant.
moisture which may be in the refrigerant system EVAPORATOR COIL: The coil is located in the
(Fig.3). A/C housing. Its function is to remove heat and de-
COMPRESSOR: The 10PA17 Compressor is a humidify the air before it enters the vehicle.
fixed displacement compressor. The purpose of the FIXED ORIFICE TUBE: The orifice tube is lo-
compressor is to compress the low-pressure refriger- cated in the outlet line of the condenser. The inlet
ant vapor into a high pressure, high temperature va- and outlet ends have a screen to filter the refriger-
por. The compressor is serviced as a assembly only. ant. O-rings on the orifice tube body prevent the re-
CLUTCH PULLEY AND COIL: They are frigerant from bypassing the orifice. The orifice tube
mounted on the compressor providing a way to drive is used to meter the flow of liquid refrigerant into the
the compressor. The compressor clutch and coil are evaporator core.
the only serviced parts on the 10PA17 compressor. HIGH PRESSURE RELIEF VALVE: The valve is
When the compressor is not in operation, the pulley located on the compressor manifold (Fig.4, 5). The
free wheels on the clutch hub bearing. When the coil valve is used to prevent excessive pressure build up.
is energized the clutch plate is magnetically engaged This prevents damage to the compressor and other
with the pulley and turns the compressor shaft. system components.

3. ZJ HEATING AND AIR CONDITIONING 24 - 3
HIGH-PRESSURE CUT-OUT SWITCH: The
switch is located on the discharge line (Fig.4, 5).The
switch is wired in series with compressor clutch. The
switch interrupts power to the compressor clutch,
when excessive pressure is present.
REFRIGERANT LINES: The lines are used to
carry the refrigerant between the various system
components. The barrier hose design is used for the
air conditioning system on this vehicle. The ends of
the A/C hoses are made from light-weight aluminum
and use new braze-less fittings.
SPRING LOCK COUPLER: The coupler is used
to attach A/C lines and other components. The cou-
pling is held together by a garter spring inside a cir-
cular cage. When the coupling is connected together,
the flared end of the female fitting slips behind the
garter spring inside the cage of the male fitting. The
garter spring and cage prevent the flared end of the
female fitting from pulling out of the cage. O-rings
are used to seal the coupling. These O-rings are com-
patible with R-134a refrigerant and must be replaced
with O-rings made of the same material. A secondary
clip is installed at the factory for added blow-off pro- Fig. 5 A/C Components 5.2L Engine
tection.
SERVICE PORTS: The low pressure service port ATC controller. The controller receives the signal
is attached to the refrigerant line (Fig.4, 5). The high from the sensor and determines the outside air tem-
pressure service port is attached to the compressor perature. This information is only provided when the
manifold. These ports are used to attach A/C gauges. vehicle is in motion.
After servicing the refrigerant system, always install IN-VEHICLE SENSOR: The sensor is located be-
service port caps. neath the right center air outlet. It is a temperature
sensitive resistor which provides a signal to ATC con-
troller. A small fan is used to draw inside air passed
the sensor. The controller receives the signal from
the sensor and determines the inside air tempera-
ture.
SOLAR SENSOR: The sensor is mounted to the
top of the instrument panel defroster grille. The sen-
sor is a photo diode which responds to light intensity.
The controller receives the signal from the sensor
and determines the sun light intensity.
REFRIGERANT
This system uses R-134a refrigerant. It is a non-
toxic, non-flammable, clear color-less liquified gas.
R-134a refrigerant is not compatible with R-12 re-
frigerant in an air conditioning system. A small
amount of R-12 in a R-134a system will cause com-
pressor failure, refrigerant oil sludge or poor A/C per-
formance.
New service port couplers have been used to ensure
that the system is not accidentally filled with the
Fig. 4 A/C Components 4.0L Engine wrong refrigerant (R-12).
R-134a refrigerant requires a special type of com-
ATC SENSORS pressor oil (ND8 PAG). When adding oil, make sure
AMBIENT TEMPERATURE SENSOR: The sen- that it is designed to be used in the R-134a system.
sor is located in front of the condenser. It is a tem-
perature sensitive resistor which provides a signal to

4. 24 - 4 HEATING AND AIR CONDITIONING ZJ
REFRIGERANT EQUIPMENT
WARNING: EYE PROTECTION MUST BE USED
WHEN SERVICING AN AIR CONDITIONING REFRIG-
ERANT SYSTEM. TURN OFF (ROTATE CLOCKWISE)
ALL VALVES ON THE EQUIPMENT BEING USED
BEFORE PROCEEDING WITH THIS OPERATION.
PERSONNEL INJURY CAN RESULT.
Chrysler Corporation recommends a (R-134a) recy-
cling device that meets SAE standard J2210 be used
when servicing the refrigerant system. Contact an
automotive service equipment supplier for refrigerant
recycling equipment that is available in your area.
Refer to the operating instructions provided with the
recycling equipment for proper operation.
MANIFOLD GAUGE SET
A R-134a manifold gauge set (Fig. 6) may be
needed in conjunction with the charging and or re-
covery/recycling device. The service hoses on the
gauge set being used should have manual (turn
wheel) or automatic back flow valves at the service Fig. 6 R-134a Manifold Gauge Set
port connector ends. This will prevent refrigerant
from being release into the atmosphere. RECOVERY/RECYCLING/EVACUATION/
CHARGING HOSE
LOW PRESSURE GAUGE HOSE The center manifold hose (YELLOW or WHITE
The low pressure hose (BLUE with BLACK STRIP) with BLACK STRIP) is used to recover, evacuate and
attaches to the low side service port. This port is lo- charge the refrigerant system. When the low or high
cated at the right rear of the engine compartment in pressure valves on the manifold gauge set are
the condenser-to-evaporator line. opened, the refrigerant in the system will escape
HIGH PRESSURE GAUGE HOSE through this hose.
The high pressure hose (RED with BLACK STRIP) Refer to the Recovery/Recycling device operators
attaches to the discharge service port. This port is lo- manual for proper procedures.
cated on the compressor plumbing or manifold.

5. ZJ HEATING AND AIR CONDITIONING 24 - 5
WARNINGS, CAUTIONS AND SERVICE PRECAUTIONS
WARNINGS CAUTIONS
WARNING: THE AIR CONDITIONING SYSTEM CON- CAUTION: Liquid refrigerant is corrosive to metal
TAINS REFRIGERANT UNDER HIGH PRESSURE. surfaces. Follow the operating instructions supplied
SEVERE PERSONAL INJURY MAY RESULT FROM with equipment being used.
IMPROPER SERVICE PROCEDURES. REPAIRS
SHOULD ONLY BE PERFORMED BY QUALIFIED
SERVICE PERSONNEL. CAUTION: Never add R-12 to a system designed to
use R-134a. Damage to the system will result.
WARNING: AVOID BREATHING A/C REFRIGERANT
CAUTION: R-12 compressor oil can not be mixed
AND LUBRICANT VAPOR OR MIST. EXPOSURE MAY
with the R-134a compressor oil. They ARE NOT
IRRITATE EYES, NOSE AND/OR THROAT. WEAR
EYE PROTECTION WHEN SERVICING THE AIR compatible.
CONDITIONING REFRIGERANT SYSTEM. SERIOUS
EYE INJURY CAN RESULT FROM EYE CONTACT CAUTION: DO NOT use R-12 equipment or parts on
WITH REFRIGERANT. IF EYE CONTACT IS MADE, the R-134a system. Damage to the system will re-
SEEK MEDICAL ATTENTION IMMEDIATELY. sult.
WARNING: DO NOT EXPOSE REFRIGERANT TO CAUTION: Do not over charge refrigerant system.
OPEN FLAME. POISONOUS GAS IS CREATED This will cause excessive compressor head pres-
WHEN REFRIGERANT IS BURNED. AN ELEC- sure and can cause noise and system failure.
TRONIC LEAK DETECTOR IS RECOMMENDED.
SERVICE PRECAUTIONS
WARNING: IF ACCIDENTAL SYSTEM DISCHARGE Never open or loosen a connection before the refrig-
OCCURS, VENTILATE THE WORK AREA BEFORE erant has been recovered from the system.
RESUMING SERVICE. LARGE AMOUNTS OF RE- A system which has been opened or one which has
FRIGERANT RELEASED IN A CLOSED WORK AREA discharged through leakage must be evacuated before
WILL DISPLACE THE OXYGEN AND CAUSE SUFFO- charging.
CATION. DO NOT open the refrigerant system or uncap a
replacement component until you are ready to service
the system. This will prevent contamination in the
WARNING: THE EVAPORATION RATE OF R-134A
system.
REFRIGERANT AT AVERAGE TEMPERATURE AND
Before disconnecting a component from the system,
ALTITUDE IS EXTREMELY HIGH. AS A RESULT, clean the outside of the fittings thoroughly.
ANYTHING THAT COMES IN CONTACT WITH THE When disconnecting a fitting use a wrench on both
REFRIGERANT WILL FREEZE. ALWAYS PROTECT halves of the fitting. This will prevent twisting of the
SKIN OR DELICATE OBJECTS FROM DIRECT CON- refrigerant lines or tubes.
TACT WITH REFRIGERANT. Immediately after disconnecting a component from
the system, seal the open fittings with a cap or plug.
Before connecting an open fitting always install a
WARNING: R-134A SERVICE EQUIPMENT OR VEHI-
new seal. Coat the fitting and seal with clean refrig-
CLE A/C SYSTEM SHOULD NOT BE PRESSURE
erant oil before connecting.
TESTED OR LEAK TESTED WITH COMPRESSED
Tighten fittings only to the specified torque. The
AIR. SOME MIXTURES OF AIR AND R-134A HAVE aluminum fittings used in the A/C system will not
BEEN SHOWN TO BE COMBUSTIBLE AT ELEVATED tolerate over tightening.
PRESSURES. THESE MIXTURES ARE POTENTIALLY Refrigerant oil absorbs moisture from the atmo-
DANGEROUS AND MAY RESULT IN FIRE OR EX- sphere. DO NOT open an oil container until ready to
PLOSION CAUSING INJURY OR PROPERTY DAM- use and install the cap immediately after using.
AGE. Store the oil only in a clean moisture-free container.
When installing a refrigerant line avoid sharp
bends. Position the line away from the exhaust or
any sharp edges which may chafe the line.

6. 24 - 6 HEATING AND AIR CONDITIONING ZJ
Keep service tools and the work area clean. Con- CAUTION: The engine cooling system is designed
tamination of A/C system through careless work hab- to develop internal pressure of 97 to 124 kPa (14 to
its must be avoided. 18 psi). Allow the vehicle 15 minutes to cool down
(or until a safe temperature and pressure are at-
COOLING SYSTEM tained) before opening the cooling system. Refer to
To maintain the performance level of the heating/ Group 7, Cooling System.
air conditioning system, the engine cooling system
must be properly maintained.
The use of a bug screen is not recommended. Any REFRIGERANT TUBING AND FITTINGS
obstructions in front of the radiator or condenser can PRECAUTIONS
reduce the performance of the A/C and engine cooling The barrier hose design is used for the air condi-
system. tioning system on this vehicle. The ends of the A/C
The radiator and condenser uses seals to insure air hoses are made from light-weight aluminum and use
flow is directed through these components. These
new braze-less fittings.
seals must be in the proper position to maintain cool-
The A/C hoses use special connectors called QUICK
ing and A/C performance.
CONNECTS. Never attempt to disconnect a quick
WARNINGS AND CAUTIONS connect without discharging the air conditioning sys-
tem. All quick connects use two O-rings to seal the
WARNING: ANTIFREEZE IS AN ETHYLENE GLYCOL connection. The O-rings are made from a special type
BASE COOLANT AND IS HARMFUL IF SWAL- of rubber that is not affected by R-134a refrigerant.
LOWED OR INHALED. IF SWALLOWED, DRINK If O-ring replacement is required be sure to use the
TWO GLASSES OF WATER AND INDUCE VOMIT- correct type of O-ring. Failure to use the correct type
ING. IF INHALED, MOVE TO FRESH AIR AREA. of O-ring will cause the connection to leak within a
SEEK MEDICAL ATTENTION IMMEDIATELY. short period of time.
Kinks in refrigerant tubing or sharp bends in re-
WARNING: WASH SKIN AND CLOTHING THOR- frigerant hose lines will reduce the capacity of the
OUGHLY AFTER COMING IN CONTACT WITH ETH- system. A good rule for the flexible hose lines is to
YLENE GLYCOL. keep the radius of all bends at least 10 times the di-
ameter of the hose. The flexible hose lines should be
routed so they are at least 80 mm (3 in) from the en-
WARNING: KEEP OUT OF REACH OF CHILDREN gine exhaust manifold. Inspect all flexible hose lines
AND PETS. to make sure they are in good condition and properly
routed. High pressures are produced in the system
WARNING: DO NOT OPEN A COOLING SYSTEM when it is operating. Extreme care must be exercised
WHEN THE ENGINE IS AT RUNNING TEMPERA- to make sure that all connections are pressure tight.
TURE. PERSONAL INJURY CAN RESULT. Dirt and moisture can enter the system when it is
opened for repair or replacement of lines or compo-
nents. The refrigerant oil will absorb moisture
WARNING: DO NOT STORE IN OPEN OR UN- readily out of the air. This moisture will convert into
MARKED CONTAINERS. acids within a closed system.

7. ZJ HEATING AND AIR CONDITIONING 24 - 7
REFRIGERANT SERVICE AND PERFORMANCE TEST
INDEX
page page
A/C Performance Test . . . . . . ... . . . . . . . . . . . . . . 9 Partial Charge Method . . . . . . . . . . . . . . . . . . . . . . 7
Charging Refrigerant System . ... . . . . . . . . . . . . . . 7 Recovering Refrigerant System . . . . . . . . . . . . . . . . 7
Evacuating Refrigerant System .. . . . . . . . . . . . . . . 7 Refrigerant Oil . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8
Leak Testing Refrigerant . . . . ... . . . . . . . . . . . . . . 7
LEAK TESTING REFRIGERANTREVIEW charged. Moisture and air mixed with refrigerant will
WARNINGS AND CAUTIONS IN THIS raise the compressor head pressure above acceptable
operating levels. This will reduce the performance of
GROUP BEFORE LEAK TESTING.
the air conditioner and damage the compressor.
If A/C system is not cooling properly, determine if
Evacuating will boil the moisture out of the system
system is fully charged. Refer to Refrigerant System
at near room temperature. To evacuate the refriger-
Diagnosis Chart. If the system is empty evacuate the
A/C system and charge system with 0.27 kg (0.6 lbs.) ant system use following procedure:
R-134a refrigerant. Refer to Charging Refrigerant (1) Connect a suitable charging station and mani-
System for instructions. To detect a leak in the sys- fold gauge set to the vehicle.
tem, perform the following procedures. (2) Open the low and high side valves and start
(1) Position the vehicle in a wind free work area. vacuum pump. When suction gauge reads 88 kPa (26
This will aid in detecting small leaks. in. Hg) vacuum or greater, close all valves and turn
(2) Bring A/C system up to operating temperature off vacuum pump. If system fails to reach specified
and pressure. This is done by allowing the engine to vacuum, the system has a leak that must be cor-
run with the A/C on for 5 to 7 minutes. rected. If system maintains the specified vacuum for
(3) Open hood 5 minutes prior to leak test. This 5 minutes, restart the vacuum pump. Then open the
will dissipate any accumulated refrigerant in the en- suction and discharge valves and evacuate an addi-
gine compartment. tional 10 minutes.
(4) With the engine not running, use an R-134a (3) Close all valves. Turn off and disconnect the
Electronic Leak Detector and search for leaks. Move vacuum pump.
probe slowly along the bottom side of lines and fit- The system is now ready to be charged with refrig-
tings, because R-134a is heavier than air. Fittings, erant.
lines, or components that appear to be oily usually
indicates a refrigerant leak. CHARGING REFRIGERANT SYSTEMREVIEW
(5) To inspect the evaporator core for leaks. Set the WARNINGS AND CAUTIONS IN THIS
blower at low speed and the selector in FLOOR and GROUP BEFORE CHARGING SYSTEM.
RECIRC mode check for leaks at the left and right After the system has been tested for leaks and the
heater outlets. refrigerant recovered, a refrigerant charge can be in-
jected into the system. Refer to refrigerant capacities
RECOVERING REFRIGERANT SYSTEM for proper amount of refrigerant charge. Charge the
REVIEW WARNINGS AND CAUTIONS IN system using a Recovery/Recycling/Charging Station
THIS GROUP BEFORE RECOVERING REFRIG- approved for R-134a refrigerant. Refer to the instruc-
ERANT SYSTEM. tions provided with the equipment for proper opera-
R-134a refrigerant is a hydrofluorocarbon (HFC) tion.
that does not contain chlorine. R-134a refrigerant Re-
covery/Recycling Station that meets SAE standard REFRIGERANT CHARGE CAPACITY
J2210 must be used to recover the refrigerant. Refer The R-134a system charge capacity is 0.8 kg (1.75
to the operating instructions provided with the equip- lbs.).
ment for proper operation.
PARTIAL CHARGE METHODREVIEW WARNINGS
EVACUATING REFRIGERANT SYSTEMREVIEW AND CAUTIONS IN THIS GROUP BEFORE
WARNINGS AND CAUTIONS IN THIS CHARGING SYSTEM.
GROUP BEFORE EVACUATING SYSTEM. This method is used to add a partial charge to a
If the A/C system has been open to the atmosphere, system that is low on refrigerant. To perform this
it must be evacuated before the system can be procedure the evaporator inlet and outlet tube tem-

8. 24 - 8 HEATING AND AIR CONDITIONING ZJ
peratures are measured. The difference between the ature difference and refer to the Low Charge Deter-
evaporator inlet and outlet tube temperatures will mination chart to determine if an additional charge
determine the amount of charge needed. is required.
The temperature difference is measured with a (10) Record the compressor discharge pressure. If
temperature meter with one or two clamp-on Ther- pressure is higher than the pressure in the Compres-
mocouple probes. sor Discharge Pressure chart, the system could be
Before adding a partial charge check for leaks (re- overcharged. If the pressure is equal to or lower than
fer to Refrigerant Leak Testing). If found correct the chart continue with this procedure.
leak. FOR EXAMPLE: The ambient temperature is
(1) Attach manifold gauge set. 21°C (70°F). The evaporator INLET temperature is
(2) Attach probes to the inlet and outlet tubes of 12°C (54°F) and the evaporator OUTLET tempera-
the evaporator. ture is 10°C (50°F). The difference is OUTLET - IN-
(a) If a single thermocouple probe is used, attach LET = -2°C (-4°F). With a -2°C (-4°F) temperature
probe to the evaporator inlet tube just before the differential at 21°C (70°F) ambient temperature, the
collar of the quick-connect fitting. The probe must system is fully charged.
makes contact with the bottom surface of the tube. (11) Add enough refrigerant to bring system up to
(b) If dual thermocouple probes are used, attach a full charge.
probe (1) to the evaporator inlet tube and probe (2) (12) Remove the jumper wire from the cycling
to the evaporator outlet tube. Be sure to attach the switch connector and plug connector into switch.
probes just before the collar of the quick-connect
fittings. The probes must make contact with the REFRIGERANT OIL
bottom surface of the tubes. It is important to have the correct amount of oil in
(3) Open all windows or doors of the passenger the A/C system. This will ensure proper lubrication of
compartment. Set the air conditioning controls to the compressor. Too little oil will result in damage to
A/C, PANEL, RECIRC (temperature knob on full the compressor. Too much oil will reduce the cooling
cool) and blower speed on HIGH. capacity of the system.
(4) Start the engine and hold at 1,000 RPM. Allow The oil used in the 10PA17 compressor is a poly-
the engine to warm up to normal operating tempera- alkylene glycol synthetic ND8 PAG, wax-free refrig-
ture. erant oil. Only refrigerant oil of the same type should
(5) The A/C clutch may cycle depending on ambi- be used to service the system. Do not use any other
ent temperature and the state of charge. If the clutch oil. The oil container should be kept tightly capped
cycles remove cycling clutch switch connector from until it is ready for use and then capped after use to
switch located on the accumulator. Place a jumper prevent contamination. Refrigerant oil will quickly
wire between the terminals of the switch connector. absorb any moisture it comes in contact with.
(6) Hold the engine speed at 1,000 RPM.
(7) Allow 3 to 5 minutes for the A/C system to sta- OIL LEVEL CHECK
bilize. Record the temperature difference between the It will not be necessary to check oil level in the
evaporator inlet and outlet tubes. compressor or to add oil unless there has been an oil
(a) If a single probe is used, record the tempera- loss. This may be due to a rupture or leak from a
ture of the inlet tube. Then remove the probe from line, shaft seal, evaporator or condenser. Oil loss at a
the inlet tube and attach it to the outlet tube just leak point will be evident by the presence of a wet,
before the quick-connect fitting. The probe must shiny surface around the leak.
makes contact with the tube. Allow the equipment When an A/C system is assembled at the factory,
to stabilize then record the temperature of the out- all components (except the compressor) are refriger-
let tube. Subtract the inlet temperature from the ant oil free. After the system has been charged and
outlet temperature. operated, the oil in the compressor is dispersed
(b) If dual probes are used, record the tempera- through the system. The accumulator, evaporator,
ture difference between the two. condenser and compressor will retain a significant
(8) Refer to the Low Charge Determination chart amount of oil.
to determine the additional charge required. If the Refrigerant oil must be added when a accumulator,
measured temperature differential (refer to Low evaporator, condenser or compressor are replaced.
Charge Determination chart) is higher than 22°C to When the compressor is replaced, the oil must be
26°C (40°F to 47°F), add 0.4 kg. (14 oz.). drained from the replaced compressor and measured.
(9) Allow 3 to 5 minutes for the system to stabilize Drain all the oil from the new compressor. Add back
then take a second measurement. Record the temper- into the new compressor the amount of oil that was
drained out of the old compressor.

9. ZJ HEATING AND AIR CONDITIONING 24 - 9
LOW CHARGE DETERMINATION
COMPRESSOR DISCHARGE PRESSURE
The evaporator, condenser and accumulator will re- cooled to temperatures near the freezing point. As
tain a significant amount of oil (refer to the Refriger- warm damp air passes over the fins in the evapora-
ant Oil Capacities Chart). tor, the air is cooled and moisture is removed to con-
dense on the fins. During periods of high heat and
A/C PERFORMANCE TEST humidity an A/C system will be more effective in the
The air conditioning system is designed to provide RECIRC mode. With the control set to RECIRC, only
the passenger compartment with low temperature air from the passenger compartment passes through
and low humidity air. The evaporator, located in the the evaporator. As the passenger compartment air
Heater A/C unit behind the instrument panel, is dehumidifies, A/C performance levels improve.

10. 24 - 10 HEATING AND AIR CONDITIONING ZJ
A/C REFRIGERANT OIL CAPACITIES ture knob on full cool) and blower on HIGH.
(3) Start engine and hold at 1,000 RPM with A/C
clutch engaged.
(4) Engine should be warmed up with windows
and/or doors opened.
(5) Insert a thermometer in the left center A/C out-
let and operate the engine for 5 minutes.
(6) The A/C clutch may cycle depending on ambi-
ent conditions. If clutch cycles, remove the clutch cy-
cling pressure switch connector from the switch
located on the accumulator (Fig. 2). Place a jumper
wire across the terminals of the clutch cycling pres-
sure switch connector.
If the system has a intermittent operational prob-
lems or fault codes, make sure the 16 Way Connector
is properly seated (Fig. 1). To check this condition,
separate the connector halves and then connect
them. Two fault codes that could be stored as a result
of this condition are 6 and 7.
Fig. 2 Clutch Cycling Pressure Switch
(7) With the A/C clutch engaged, record the dis-
charge air temperature and the compressor discharge
pressure.
(8) Compare the discharge air temperature to the
A/C Performance (Temperature and Pressure) chart.
Fig. 1 Location of 16 Way Connector If the discharge air temperature is high, refer to the
Review Safety Precautions and Warnings before Refrigerant Service Procedures (Refrigerant Leak
proceeding with this procedure. Air temperature in Testing and Refrigerant Charge Check).
test room and in the vehicle must be 21°C (70°F) (9) Compare the compressor discharge pressure to
minimum for this test. the A/C Performance (Temperature and Pressure)
(1) Connect an engine tachometer and R-134a chart. If the compressor discharge pressure is high,
manifold gauge set. refer to the Refrigerant Service Procedures (High
(2) Set control to A/C, PANEL, RECIRC (tempera- Compressor Discharge Pressure).

11. ZJ HEATING AND AIR CONDITIONING 24 - 11
A/C PERFORMANCE (TEMPERATURE AND PRESSURE)

12. 24 - 12 HEATING AND AIR CONDITIONING ZJ
REFRIGERANT SYSTEM DIAGNOSIS

13. ZJ HEATING AND AIR CONDITIONING 24 - 13
HEATER AND AIR CONDITIONING TEST PROCEDURES
HEATER OUTPUT TEST • Plugged heater core.
If proper coolant flow is verified and outlet air tem-
PRE-DIAGNOSTIC PREPARATIONS perature is still low, a mechanical problem may exist.
Review Safety Precautions and Warnings before Possible location or cause of insufficient heat:
performing the following procedures. • Obstructed cowl air intake.
Check the radiator coolant level, drive belt tension • Obstructed Heater A/C system outlets.
and engine vacuum line connections. Also check radi- • Blend-air door not functioning properly.
ator air flow and radiator fan operation. Start engine
and allow to warm up to normal operating tempera- VACUUM CONTROL
ture. This control is used with the Heater A/C (manual)
system.
WARNING: DO NOT REMOVE RADIATOR CAP
Use an adjustable Vacuum Test Gauge (C-3707)
WHEN ENGINE IS HOT, PERSONAL INJURY CAN
and a suitable vacuum pump to test Heater A/C con-
RESULT.
trol vacuum. With a finger placed over the end of test
If vehicle has been run recently, wait 15 minutes hose (Fig. 3), calibrate vacuum control valve on the
before removing cap. Place a rag over the cap and test gauge to obtain -27 kPa (8 in. Hg.). Release and
turn it to the first safety stop. Allow pressure to es- block the end of the test hose several times to verify
cape through the overflow tube. When the system vacuum setting.
stabilizes, remove the cap completely.
MAXIMUM HEATER OUTPUT
Engine coolant is provided to the Heater A/C sys-
tem by 2 heater hoses. With engine idling at normal
running temperature, set the control to maximum
heat, floor and high blower setting. Using a test ther-
mometer, check the air temperature coming from the
floor outlets, refer to Temperature Reference chart.
TEMPERATURE REFERENCE CHART
Fig. 3 Adjust Vacuum Test Bleed Valve
ONE-WAY CHECK VALVE VACUUM TEST
(1) In the engine compartment, disconnect the
Heater A/C vacuum supply (black) hose. This hose
passes through an opening in the dash panel.
(2) Remove the vacuum check valve. This valve is
If the floor outlet air temperature is low, refer to
located on the (black) vacuum supply hose at the in-
Group 7, Cooling System for coolant temperature
take manifold.
specifications. Both heater hoses should be HOT to
(3) Connect test vacuum supply hose to the
the touch. The coolant return hose should be slightly
HEATER SIDE of the valve. In this direction the
cooler than the supply hose. If coolant return hose is
much cooler than the supply hose, locate and repair gauge should return to calibrated setting. If valve
engine coolant flow obstruction in Heater A/C system. leaks vacuum in this direction, valve replacement is
Possible locations or cause of obstructed cool- necessary.
ant flow: (4) Connect test vacuum supply hose to the EN-
• Pinched or kinked heater hoses. GINE VACUUM SIDE of the valve. Vacuum should
• Improper heater hose routing. flow through valve.
• Plugged heater hoses or supply and return ports at
cooling system connections (refer to Group 7, Cooling
System).

14. 24 - 14 HEATING AND AIR CONDITIONING ZJ
HEATER A/C CONTROL VACUUM TEST VACUUM CIRCUITS
(1) Connect the test vacuum probe to the vehicles
(black) vacuum supply hose. Position vacuum test
gauge so it can be viewed from the passenger com-
partment.
(2) Position the Heater A/C control mode selector
to DEFROST, FLOOR, BI-LEVEL, PANEL or RE-
CIRC (with A/C). Pause after each selection. The test
gauge should return to the calibrated setting of -27
kPa (8 in. Hg.) after each selection is made. If the
gauge cannot achieve the calibrated setting, a vac-
uum circuit or component has a leak.
LOCATING VACUUM LEAKS
To locate a vacuum leak, disconnect 7-way vacuum
connector behind the Heater A/C control panel. Con-
nect the calibrated vacuum hose probe to each port
in the vacuum harness connector (Fig. 4). After each
connection is made, the test gauge should return to
calibrated setting. If all circuits function properly, re-
place Heater A/C control. If not, determine the color
of the vacuum circuit that is leaking. To determine
vacuum line colors, refer to the Vacuum Circuits
chart for the Heater A/C (manual) units. Disconnect
the vacuum actuator at the other end of the circuit.
Instrument panel removal may be necessary to gain
access to some components. Block the end of the dis-
connected vacuum line. The test gauge should return
to calibrated setting. If not, that circuit has a leak
and must be repaired or replaced. If test gauge re- • Blower wheel loose on motor shaft.
turns to calibrated setting, the vacuum actuator • Blower wheel out of balance or bent.
must be replaced.
• Blower motor defective.
BLOWER MOTOR NOISE
To verify blower noise, disconnect blower motor
connector and operate the heater A/C system. If the
noise goes away check the following possible causes.
• Foreign material in the heater A/C housing around
the blower wheel.
• Blower wheel rubbing the heater A/C housing.
• Blower motor defective.
BLOWER MOTOR ELECTRICAL DIAGNOSIS
Refer to the Blower Motor Electrical System Diag-
nosis chart in this section. Also refer to Group 8W,
Wiring Diagrams for more information.
COMPRESSOR CLUTCH
The air conditioning compressor clutch electrical
circuit is controlled by the powertrain control module
Fig. 4 Vacuum Circuit Test (Fig. 5).
If the compressor clutch does not engage, verify re-
BLOWER MOTOR VIBRATION NOISE DIAGNOSIS
frigerant charge.
BLOWER MOTOR VIBRATION If the compressor clutch still does not engage,
Possible cause of blower motor vibration; check for battery voltage at the low pressure switch
• Blower motor assembly loose in heater A/C housing.

15. ZJ HEATING AND AIR CONDITIONING 24 - 15
BLOWER MOTOR ELECTRICAL SYSTEM DIAGNOSIS

16. 24 - 16 HEATING AND AIR CONDITIONING ZJ
HIGH PRESSURE RELIEF VALVE
The high pressure relief valve is located on the
compressor manifold (Fig. 6). The valve vents only a
small amount of refrigerant necessary to reduce sys-
tem pressure and then reseats itself. This prevents
damage to the air conditioning system if excessive
pressure develops. Excessive pressure may be caused
by condenser air flow blockage, refrigerant over-
charge, or air and moisture in the system. The valve
is calibrated to vent at a pressure of 3445 to 4135
kPa (500 to 600 psi). If a valve has vented a small
amount of refrigerant, it does not necessarily mean
the valve is defective.
Fig. 5 Powertrain Control Module
located on the accumulator. If voltage is not detected,
refer to Group 8W, Wiring Diagrams and the Power-
train Diagnostic Procedures Manual for diagnostic in-
formation.
If voltage is detected at the cut-off switch, recon-
nect switch. Then check for battery voltage between
the compressor clutch connector terminals. If voltage
is detected, perform A/C Clutch Coil Tests.
CLUTCH COIL TESTS
(1) Verify battery state of charge. Test indicator in
battery should be green.
(2) Connect an ammeter (0-10 ampere scale) in se- Fig. 6 High Pressure Relief Valve
ries with the clutch coil terminal. Use a volt meter
(0-20 volt scale) with clip leads measuring voltage AIR CONDITIONING CYCLING SWITCH
across the battery and A/C clutch. The switch is mounted on a Schrader-Type valve
(3) With A/C control in A/C mode and blower at fitting on the top of accumulator. A valve depressor,
low speed, start the engine and run at normal idle. is located inside the threaded end of the pressure
(4) The A/C clutch should engage immediately and switch. It presses on the Schrader-Type valve stem as
the clutch voltage should be within 2 volts of the bat- the switch is mounted. This allows the evaporator
tery voltage. If the A/C clutch does not engage, test outlet pressure inside the accumulator to control
the fusible link. switch operation. The electrical switch contacts are
(5) The A/C clutch coil is acceptable if the current normally open when the suction evaporator outlet
draw is 2.0 to 3.7 amperes at 11.5 to 12.5 volts at pressure is approximately 172 kPa (25 psi) or lower.
clutch coil. This is with the work area temperature at They will close when the suction evaporator outlet
21°C (70°F). If voltage is more than 12.5 volts, add pressure rises to approximately 296 kPa (43 psi) or
electrical loads by turning on electrical accessories above. Lower ambient temperatures, below approxi-
until voltage reads below 12.5 volts.
mately -1°C (30°F) during cold weather will also open
If coil current reads zero, the coil is open and
the clutch cycling pressure switch contacts. This is
should be replaced. If the ammeter reading is 4 am-
due to the pressure/temperature relationship of the
peres or more, the coil is shorted and should be re-
refrigerant in the system. The electrical switch con-
placed. If the coil voltage is not within two volts of
the battery voltage, test clutch coil feed circuit for ex- tacts control the electrical circuit to the compressor
cessive voltage drop. magnetic clutch coil. When the switch contacts are

17. ZJ HEATING AND AIR CONDITIONING 24 - 17
closed, the clutch coil is energized and the A/C clutch rator grille next to the glove box. The paper should
is engaged to drive the compressor. cling to the grille. If the paper does not cling to the
The cycling switch controls the evaporator coil re- grille, proceed with the following steps:
frigerant flow. It also prevents evaporator icing and (1) Inspect the aspirator hose routing. The hose is
the blockage of airflow. connected to the heating and air conditioning unit
just above the carpeting on the transmission tunnel.
FIXED ORIFICE TUBE The hose should be long enough to reach the nipple if
The fixed orifice tube is located in the liquid line it is routed correctly.
near the condenser. It has filter screens on the inlet (2) Make sure that the hose is not blocked by dis-
and outlet ends of the tube body. The filter screens connecting the hose and checking for blockage.
act as a strainer for the liquid refrigerant flowing (3) Install the hose on the nipple using a new
through the fixed orifice opening. O-rings, on the clamp.
tube body, prevent the high pressure liquid refriger-
ant from bypassing the orifice. Adjustments cannot ATC DIAGNOSTICS
be made to the fixed orifice tube. If it becomes The ATC controller is designed with on-board diag-
clogged or damaged, replace the condenser to evapo- nostics. It is capable of troubleshooting input and
rator tube. output circuits of the controller. When a fault is de-
The fixed orifice tube assembly is the restriction tected and in memory, an ‘‘Er’’ is momentarily dis-
between the high and low pressure liquid refrigerant. played, but only once during an ignition cycle. There
It meters the flow of liquid refrigerant into the evap- are three different groups of testing features that
orator core. Evaporator temperature is controlled by this system is capable of:
sensing pressure within the evaporator with a pres- (1) Fault Codes
sure-operated electric switch. The pressure switch (2) Input Circuit Testing
controls compressor operation as necessary to pre- (3) Output Circuit Testing/Actuator Tests
vent evaporator freeze-up.
The condenser to evaporator tube should be re- DIAGNOSTICS TEST SELECTOR
placed whenever a compressor is replaced for lack of The test selector is located in the same location as
performance (internal damage). the temperature control point. It is used to display
fault codes, identify test mode and show the value of
HIGH PRESSURE RELIEF VALVE each circuit being tested.
A pressure relief valve is used to prevent excessive (1) If the floor (bottom) arrow is showing, the test
high pressure build up of 3445 to 4135 kPa (500 to selector value will be a range of numbers below 0
600 psi) and above. This will prevent damage to the (Fig. 7).
compressor and other system components. The pres-
sure relief valve is located on the rear end of the
compressor manifold.
HIGH PRESSURE CUT-OUT SWITCH
The high pressure cut-out switch is located at the
plumbing connection on the compressor manifold.
When the discharge pressure reaches 3100 to 3375
kPa (450 to 490 psi), the switch interrupts the elec-
trical power to the compressor clutch. This will pre-
vent compressor operation when compressor
discharge pressure approaches high levels.
ATC-TEMPERATURE AND BLOWER SPEED
VARIATIONS
If the outlet air temperature and blower speed var-
ies, the air aspirator hose could either be discon-
nected or blocked. In order for the in-vehicle
Fig. 7 Test Selector Values Below 0
temperature sensor to function, the aspirator hose (2) If the stickman shows no arrows, the test selec-
draws air from the passenger compartment. tor value will be a range of numbers between 0 and
Check the operation of the aspirator hose and fan 99 (Fig. 8).
by operating the system in the panel air mode. Set (3) If the panel (middle) arrow is showing, the test
the fan on high and in recirculating mode. Place a 50 selector value will be a range of numbers between
by 50 mm (2 by 2 inch) square paper over the aspi- 100 and 199 (Fig. 9).

18. 24 - 18 HEATING AND AIR CONDITIONING ZJ
one CLICK in either direction. Again the stickman
and arrows are not shown in test selector mode. Also,
you have the option of monitoring or testing another
circuit (Fig. 11).
Fig. 8 Test Selector Values Between 0 and 99
Fig. 11 Return to Test Selector Mode
ENTER DIAGNOSTICS
To enter the diagnostics, perform the following:
(1) Depress the A/C and RECIRC buttons simulta-
neously and hold. Rotate the control knob clockwise
one CLICK.
(2) If you continue to hold the A/C and RECIRC
buttons you will see the display completely light up.
This is the Segment Test.
(3) After viewing the Segment Test, release the A/C
and RECIRC buttons. This will put the test selector
at 00, the Select Test level.
Fig. 9 Test Selector Values Between 100 and 199 At this point a number of tests can be performed.
(4) If the panel (middle) and defrost (top) arrows However, the Fault Code Diagnostics should be pre-
are showing, the test selector value will be a range of formed now.
numbers between 200 and 255 (Fig. 10).
FAULT CODE DIAGNOSTICS
The codes are two digit numbers that identify
which circuit is malfunctioning. There are two differ-
ent kinds of fault codes.
(1) Current Fault Codes are divided into two cate-
gories; input faults and system faults. Current faults
means they are present right now.
(2) Historical Fault Codes are referred to as histor-
ical faults or faults that are stored in memory. His-
torical faults are an indication that a circuit failed
previously, but is OK right now. A majority of histor-
ical fault codes are caused by wiring or connector
problems.
CAUTION: A battery disconnect will erase all faults
stored in Read Available Memory (RAM). It is recom-
Fig. 10 Test Selector Values Between 200 and 255 mended that all faults be recorded before they are
erased.
During diagnostics you may return to the test se-
lector mode. Simply turning the temperature control

19. ZJ HEATING AND AIR CONDITIONING 24 - 19
While 00 is displayed, push either A/C or RECIRC (3) To see the input, press the A/C or RECIRC but-
button. The stickman will appear indicating you have ton. The digits displayed will represent the input
entered the fault section. The numbers displayed will seen by the controller.
range from 00 to 64.
Fault codes will appear and repeat if there are OUTPUT CIRCUIT TESTING / ACTUATOR
more than one. Record the fault codes and refer to TESTS
the Current and Historical Fault Code Charts. If After diagnostics is entered, you have the ability to
there are no fault codes, the display remains at 00. view or monitor, override and test the output circuits.
If Fault Code 25 or 29 is displayed, the ATC Con- If a failure occurs in the output circuit, test by over-
trol Module must be replaced before any further test- riding the system. Test it through its full range of op-
ing is performed. eration. When the override control has been
For more detailed information about a fault code, activated, the display will be flashing. The control
refer to the Input Circuit Testing or Output Circuit will display feedback information about the circuit
Testing/Actuator Tests. being tested.
Use the following steps to view the output com-
CLEARING FAULT CODES
Current faults are cleared whenever the problem mands from the controller:
goes away. To clear the historical faults, press and (1) Enter the diagnostics mode.
hold either A/C or RECIRC for 3 seconds. The faults (2) Turn the knob until the test you are looking for
have cleared when 2 horizontal bars appear in the appears (refer to Circuit Testing chart).
display screen. (3) To see the output, press the A/C or RECIRC
button. The digits displayed will represent the output
INPUT CIRCUIT TESTING from the controller.
After diagnostics is entered, the status of input cir- (4) To enter the actuator test, press the A/C or RE-
cuits can be viewed or monitored. If a failure occurs CIRC button. The display will blink, indicating you
within an input circuit the controller will display a are in an actuator testing mode. Manual tests are
‘‘?’’ for unknown values, a ‘‘OC’’ for an open circuit those in which you will have to continuously press
and a ‘‘SC’’ for a shorted circuit. the A/C or RECIRC button to control the output.
Use the following steps to view the inputs into the Press the A/C or RECIRC button once to run the au-
controller: tomatic tests.
(1) Enter the diagnostics mode.
(2) Turn the knob until the test you are looking for
appears (refer to Circuit Testing chart).

20. 24 - 20 HEATING AND AIR CONDITIONING ZJ
CURRENT FAULTS

21. ZJ HEATING AND AIR CONDITIONING 24 - 21
HISTORICAL FAULTS

22. 24 - 22 HEATING AND AIR CONDITIONING ZJ
CIRCUIT TESTING

23. ZJ HEATING AND AIR CONDITIONING 24 - 23
CIRCUIT TESTING (CONT.)

24. 24 - 24 HEATING AND AIR CONDITIONING ZJ
ELECTRICAL CIRCUITS
BLEND AIR DOOR ACTUATOR DRIVE CIRCUIT AIR INLET/RECIRC DOOR ACTUATOR DRIVE
CIRCUIT
MODE DOOR ACTUATOR DRIVE CIRCUIT FRONT PANEL MODE CONTROL

25. ZJ HEATING AND AIR CONDITIONING 24 - 25
FRONT PANEL BLOWER/FAN CONTROL SOLAR SENSOR
AMBIENT TEMPERATURE SENSOR
IN-VEHICLE TEMPERATURE SENSOR

26. 24 - 26 HEATING AND AIR CONDITIONING ZJ
CHRYSLER COLLISION DETECTION BUS
CALIBRATION AND CPU DATA

27. ZJ HEATING AND AIR CONDITIONING 24 - 27
COMPRESSOR SERVICE
INDEX
page page
A/C Compressor Noise . . . . . . . . . . . . . . . . . . . . . 27 Compressor High-Pressure Relief Valve . . . . . . . . . 30
Compressor . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 27 Compressor Manifold . . . . . . . . . . . . . . . . . . . . . . 27
Compressor Clutch / Coil Assembly . . . . . . . . . . . . 29
A/C COMPRESSOR NOISE (6) Remove compressor. If refrigerant lines were
Noises that develop during air conditioning opera- not removed, lift compressor/clutch assembly and tie
tion can often be misleading. it to a suitable component.
Drive belts are speed sensitive. At different engine
speeds belts can make noises which can be mistaken INSTALLATION
for compressor noise. (1) Position compressor on mount.
First proceed with the following steps: (2) Install and tighten the bolts to 27 N⅐m (20 ft.
(1) Select a quiet area for testing. Switch compres- lbs.) torque.
sor on and off several times to clearly identify com- (3) Connect the compressor clutch wire lead.
pressor noise. (4) Install and tighten the serpentine belt (refer to
(2) Tighten all compressor mounting bolts to cor- Group 7, Cooling System).
rect torque. Check condition and adjustment of com- (5) Connect the negative cable to the battery.
pressor drive belt. Verify refrigerant lines are not (6) If refrigerant lines were removed, install the
contacting other components. lines to the manifold an use new O-rings.
(3) Test vehicle; if noise persists, continue trouble (7) Evacuate and charge the system.
shooting system for source of noise. Refer to the
Compressor and Clutch Diagnosis Charts. COMPRESSOR MANIFOLD
REVIEW WARNINGS AND CAUTIONS IN
COMPRESSOR THIS GROUP BEFORE PROCEEDING WITH
THIS PROCEDURE.
REMOVAL
REVIEW WARNINGS AND CAUTIONS IN REMOVAL
THIS GROUP BEFORE PROCEEDING WITH (1) Disconnect the negative cable from the battery.
THIS PROCEDURE. (2) Recover the refrigerant system into a recovery/
The A/C compressor may be removed and reposi- recycle device.
tioned without recovering the refrigerant system. To (3) Remove A/C lines from the manifold.
remove the compressor clutch/coil assembly, engine, (4) Remove compressor manifold bolts.
cylinder head or generator refrigerant recovery is not (5) Remove manifold.
necessary.
(1) Disconnect the negative cable from the battery. INSTALLATION
(2) Loosen and remove the serpentine belt (refer to (1) Install new seal and position the manifold onto
Group 7, Cooling System). the compressor.
(3) Disconnect compressor clutch wire lead. (2) Install compressor manifold bolts and tighten
(4) If the compressor must be removed from the ve- to 25 N⅐m (19 ft. lbs.) torque.
hicle, recover the refrigerant system into a recovery/ (3) Install new O-rings on A/C lines and install
recycle device. Remove refrigerant lines from lines.
compressor. (4) Connect the negative cable to the battery.
(5) Remove compressor attaching bolts. (5) Evacuate and charge system.

28. 24 - 28 HEATING AND AIR CONDITIONING ZJ
COMPRESSOR AND CLUTCH DIAGNOSIS

29. ZJ HEATING AND AIR CONDITIONING 24 - 29
COMPRESSOR CLUTCH / COIL ASSEMBLY
REMOVAL
(1) Remove compressor refer to compressor re-
moval procedure.
(2) Remove the compressor shaft bolt (Fig. 1). A
band type oil filter removal tool can be placed around
the clutch plate to aid in bolt removal.
Fig. 3 Removing Pulley Snap Ring
Fig. 1 Compressor Shaft Bolt and Clutch Plate
(3) Tap the clutch plate with a plastic hammer and
remove clutch plate and shim (Fig. 2).
CAUTION: Do not use screwdrivers between the
clutch plate assembly and pulley to remove front
plate. This may damage the front plate assembly.
Fig. 4 Clutch Coil Snap Ring
INSPECTION
Examine frictional faces of the clutch pulley and
Fig. 2 Clutch Plate and Shim(s) front plate for wear. The pulley and front plate
(4) Remove pulley retaining snap ring with Snap should be replaced if there is excessive wear or scor-
Ring Pliers (C-4574) and slide pulley assembly off of ing.
compressor (Fig. 3). If friction surfaces are oily, inspect shaft nose area
(5) Remove coil wire clip screw and wire harness. of the compressor for oil. Remove the felt from the
(6) Remove snap ring retaining field coil onto com- front cover. If the felt is saturated with oil, the shaft
seal is leaking and the compressor must be replaced.
pressor housing (Fig. 4). Slide field coil off of com-
Check bearing for roughness or excessive leakage
pressor housing.
of grease. Replace bearing as required.

30. 24 - 30 HEATING AND AIR CONDITIONING ZJ
INSTALLATION proper air gap is not obtained, add or subtract shims
(1) Align pin in back of field coil with hole in com- until desired air gap is obtained.
pressor end housing and position field coil into place. (8) Install compressor shaft bolt. Tighten bolt to 13
Make sure that lead wires are properly routed and N⅐m (115 in. lbs.) torque.
fasten with the wire clip retaining screw. Shims may compress after tightening shaft
(2) Install field coil retaining snap ring with Snap nut. Check air gap in four or more places to
Ring Pliers (C-4574). The bevel side of the snap ring verify if air gap is still correct. Spin pulley for
must be outward. Also both eyelets must be to the final check.
right or left of the pin on the compressor. Press snap (9) Connect the negative cable to the battery.
ring to make sure it is properly seated in the groove.
CLUTCH BREAK-IN
CAUTION: If snap ring is not fully seated it will vi- After a new clutch has been installed cycle the A/C
brate out, resulting in a clutch failure and severe clutch 20 times (5 sec. on and 5 sec. off). During this
damage to the front face of the compressor. procedure, set the system to the A/C mode, engine RPM
at 1500 - 2000 and high blower speed. This procedure
(3) Install pulley assembly to compressor. If neces- (burnishing) will seat the opposing friction surfaces and
sary, tap gently with a block of wood on the friction provide a higher clutch torque capability.
surface (Fig. 5).
COMPRESSOR HIGH-PRESSURE RELIEF VALVE
CAUTION: Do not mar the pulley frictional surface. REVIEW WARNINGS AND CAUTIONS IN
THIS GROUP BEFORE PROCEEDING WITH
THIS PROCEDURE.
REMOVAL
(1) Disconnect the negative cable from the battery.
(2) Recover refrigerant system into a recovery/recy-
cle device.
(3) Rotate the high pressure relief valve counter-
clockwise and separate relief valve from the vehicle
(Fig. 6).
Fig. 5 Installing Pulley Assembly
(4) Install pulley assembly retaining snap ring
(bevel side outward) with Snap Ring Pliers (C-4574).
Press the snap ring to make sure it is properly
seated in the groove.
(5) If the original front plate assembly and pulley
assembly are to be reused, the old shim(s) can be
used. If not, place a stack of shim(s) equal to the old
shim(s) on the shaft against the shoulder.
(6) Install front plate assembly onto shaft.
(7) With the front plate assembly tight against the Fig. 6 High Pressure Relief Valve
shim(s), measure the air gap between front plate and INSTALLATION
pulley face with feeler gauges. The air gap should be (1) Install the high pressure relief valve.
between 0.35 and 0.65 mm (.014 and .026 in.) If (2) Evacuate and charge system.

31. ZJ HEATING AND AIR CONDITIONING 24 - 31
COMPONENT SERVICE
INDEX
page page
Accumulator . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 43 High Pressure Cut-Out Switch . . . . . . . . . . . . . . . . 44
Ambient Air Temperature Sensor . . . . . . . . . . . . . . 40 In-Vehicle Temperature Sensor . . . . . . . . . . . . . . . 40
Blower Motor and Wheel . . . . . . . . . . . . . . . . . . . . 32 Liquid Line . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 43
Blower Motor Resistor . . . . . . . . . . . . . . . . . . . . . . 33 Panel / Defrost Door . . . . . . . . . . . . . . . . . . . . . . . 39
Condenser . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 41 Panel / Defrost Door Actuator . . . . . . . . . . . . . . . . 39
Control Panel . . . . . . . . . . . . . . . . . . . . . . . . . . . . 32 Rear Floor Heat Duct . . . . . . . . . . . . . . . . . . . . . . 41
Defroster Duct . . . . . . . . . . . . . . . . . . . . . . . . . . . 41 Recirculating Air Door . . . . . . . . . . . . . . . . . . . . . . 36
Discharge Line . . . . . . . . . . . . . . . . . . . . . . . . . . . 43 Recirculating Air Door Actuator . . . . . . . . . . . . . . . 36
Evaporator Core . . . . . . . . . . . . . . . . . . . . . . . . . . 35 Refrigerant Lines . . . . . . . . . . . . . . . . . . . . . . . . . 31
Heat / Defrost and Panel / Defrost Door Motor . . . . 38 Solar Sensor . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 40
Heat / Defrost Door . . . . . . . . . . . . . . . . . . . . . . . . 38
Heat / Defrost Door Actuator . . . . . . . . . . . . . . . . . 37 Temperature / Blend Air Door . . . . . . . . . . . . . . . . 37
Heater Core . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 35 Temperature / Blend Air Door Motor . . . . . . . . . . . . 37
Heater—A/C Unit . . . . . . . . . . . . . . . . . . . . . . . . . 33 Vacuum Reservoir . . . . . . . . . . . . . . . . . . . . . . . . . 44
REFRIGERANT LINES (3) Close the tool and push into the open side of
REVIEW WARNINGS AND CAUTIONS IN the cage to expand garter spring and release female
THIS GROUP BEFORE PERFORMING THE fitting.
The garter spring may not release if the tool is
FOLLOWING PROCEDURE.
cocked while pushing it into the cage opening.
REMOVAL (4) After garter spring is expanded, pull fittings
(1) Recover refrigerant system into a recovery/recy- apart within the tool.
(5) Remove the tool from the disconnected cou-
cle device.
pling.
(2) Remove the secondary clip from the coupling.
(6) Separate the two ends of the coupling.
Fit the appropriate Spring Lock Coupling Tool from
A/C Tool Kit 6125 (Fig. 1). INSTALL
(1) Check to ensure that the garter spring is in the
cage of the male fitting. If the garter spring is miss-
ing, install a new spring by pushing it into the cage
opening. If the garter spring is damaged, remove it
from the cage with a small wire hook (DO NOT use a
screwdriver) and install a new spring.
(2) Clean all dirt or foreign material from both
pieces of the coupling.
(3) Install new O-rings on the male fitting.
CAUTION: Use only the specified O-rings as they
are made of a special material for the R-134a sys-
tem. The use of any O-ring other than the specified
O-ring may allow the connection to leak intermit-
tently during vehicle operation.
(4) Lubricate the male fitting and O-rings and the
inside of the female fitting with clean R-134a (SP20
PAG) refrigerant oil.
(5) Fit female fitting to male fitting and push until
garter spring snaps over flared end of female fitting.
(6) Ensure coupling engagement by pulling back on
Fig. 1 Spring Lock Coupling Disconnect the line.
(7) Install secondary clip on coupling.

32. 24 - 32 HEATING AND AIR CONDITIONING ZJ
CONTROL PANEL
REMOVAL
(1) Disconnect the negative cable from the battery.
(2) Remove ash tray.
(3) Remove screws holding center cluster bezel (Fig. 2).
Fig. 4 Vacuum Connector
INSTALLATION
(1) If the vehicle is equipped with Heater A/C
(manual), connect the vacuum connector.
(2) Connect electrical connectors.
(3) Install control panel and tighten screws.
(4) Install center bezel.
(5) Install and tighten the center bezel screws.
(6) Install ash tray.
(7) Connect the negative cable to the battery.
BLOWER MOTOR AND WHEEL
The blower motor and wheel are located under the
glove box and can be removed from the passenger
compartment.
REMOVAL
(1) Disconnect the negative cable from the battery.
(2) Disconnect the blower motor cooling tube (Fig. 5).
(3) Remove the blower motor electrical connector
from the retainer. Disconnect the electrical connector
(Fig. 5).
Fig. 2 Remove Center Bezel Retaining Screws (4) Remove the blower motor and wheel assembly
(4) Remove center bezel. mounting screws (Fig. 5).
(5) Remove the control panel screws (Fig. 3). (5) Remove the blower motor and wheel assembly.
(6) Remove the control panel. (6) Remove the blower motor wheel retainer clip
(Fig. 6).
(7) Pull the blower motor wheel off of the blower
motor shaft.
INSPECTION
Inspect the blower motor seal for damage.
INSTALLATION
(1) Press the blower motor wheel onto the blower
motor shaft. Be sure the flat on the blower motor
shaft lines up with the flat inside the wheel.
(2) Install the retainer clip. The ears of the re-
Fig. 3 Heater A/C Control Panel tainer clip must be over the flat surface on the motor
(7) Disconnect the electrical connector(s). shaft.
(8) Disconnect the vacuum connector on Heater (3) Be sure the seal is installed on the blower mo-
A/C (manual) vehicles (Fig. 4). tor housing (Fig. 7).
(4) Install the blower motor and wheel assembly.
(5) Install and tighten blower motor and wheel as-
sembly screws.

33. ZJ HEATING AND AIR CONDITIONING 24 - 33
Fig. 7 Blower Motor Seal
Fig. 5 Blower Motor
Fig. 6 Blower Motor Wheel
(6) Connect the electrical connector and install into
the retainer.
(7) Connect the blower motor cooling tube.
(8) Connect the negative cable to the battery. Fig. 8 Blower Motor Resistor (ATC Shown)
INSTALLATION
BLOWER MOTOR RESISTOR (1) Install the blower motor resistor. Install and
The blower motor resistor is located under the tighten the screws.
glove box and can be removed from the passenger (2) Connect the resistor connectors.
compartment. (3) Connect the negative cable to the battery.
REMOVAL
HEATER—A/C UNIT
(1) Disconnect the negative cable from the battery.
(2) Remove the blower motor resistor connector(s). REMOVAL
(3) Remove the resistor retaining screws. (1) Disconnect the negative cable from the battery.
(4) Remove the blower motor resistor (Fig. 8). (2) Recover the refrigerant system into a recovery/
recycle device.

34. 24 - 34 HEATING AND AIR CONDITIONING ZJ
(3) Disconnect the A/C hoses from the evaporator
lines (Fig. 9).
(4) Drain the cooling system (refer to Group 7,
Cooling System).
(5) Disconnect the heater hoses from the heater
core lines (Fig. 9).
Fig. 11 Powertrain Control Module (PCM)
Fig. 9 Heater A/C Unit (Shown from Engine
Compartment) (10) Remove the defrost duct (Fig. 12).
(6) Remove the coolant reserve/overflow bottle (Fig.
10).
Fig. 12 Defrost Duct
(11) Disconnect the rear floor heat duct from the
center adaptor heat duct (Fig. 13).
(12) Disconnect the electrical connections.
(13) Remove the attaching nuts from the studs in
the passenger compartment side of the dash panel
(Fig. 14).
(14) Remove the Heater A/C unit from the vehicle.
INSTALLATION
(1) Position the Heater A/C unit into the dash
panel. Be sure the drain tube is positioned in the
Fig. 10 Coolant Reserve/Overflow Bottle—Typical dash panel drain hole.
(7) DO NOT disconnect the 60-way connector from (2) Install the passenger compartment attaching
the powertrain control module (PCM) - (Fig. 11). Re- nuts (Fig. 14). Tighten the nuts to 4.5 N⅐m (40 in.
move the PCM and set aside. lbs.) torque.
(8) Remove the attaching nuts from the studs on (3) Install the attaching nuts on the engine com-
the engine compartment side of the dash panel (Fig. partment side of the dash panel (Fig. 9). Tighten the
9). nuts to 7 N⅐m (60 in. lbs.) torque.
(9) Remove the instrument panel (refer to Group (4) Connect the heater hoses to the heater core
23, Body). lines.

35. ZJ HEATING AND AIR CONDITIONING 24 - 35
HEATER CORE
REMOVAL
(1) Remove the Heater A/C unit from the vehicle.
(2) Remove the heater core retaining screws.
(3) Pull the heater core straight out of the housing
(Fig. 15).
Fig. 13 Rear Floor Heat Duct
Fig. 15 Heater Core
INSTALLATION
(1) Install the heater core into the housing.
(2) Position the clips over the heater core tubes.
Install and tighten the screws.
(3) Install the Heater A/C unit into the vehicle.
EVAPORATOR CORE
Fig. 14 Heater A/C Unit (Shown from Passenger REMOVAL
Compartment) (1) Remove the Heater A/C unit from the vehicle.
(2) Turn the Heater A/C unit upside down.
(5) Connect the A/C hoses to the evaporator lines.
(3) Remove the retaining screws holding the two
(6) Install the coolant reserve/overflow bottle.
halves together. Remove the center adaptor heat duct
(7) Install the powertrain control module (PCM). (Fig. 16) and remove the screw.
(8) Install the defrost duct. (4) Carefully turn the Heater A/C unit over. Re-
(9) Connect the rear floor heat duct to the center move the top half of the unit (Fig. 17).
adaptor heat duct. Check that the carpet is not inter- (5) Remove the evaporator out of the unit.
fering with any duct outlets.
(10) Connect the electrical connectors. INSTALLATION
(11) Install the instrument panel (refer to Group Add 2 ounces oil to the evaporator if it was re-
23, Body). placed.
(12) Fill the cooling system (refer to Group 7, Cool- (1) Position the evaporator in the bottom half of
ing System). the Heater A/C unit.
(13) Connect the negative cable to the battery. (2) Position the top half of the Heater A/C unit in
(14) Evacuate and charge the system. place. Carefully turn the unit over. Install and
(15) Start the vehicle and check for proper opera- tighten the retaining screws.
tion of the Heater A/C system. (3) Snap on the center adaptor heat duct.

36. 24 - 36 HEATING AND AIR CONDITIONING ZJ
Fig. 16 Center Adaptor Heat Duct
Fig. 18 Recirculating Air Door Actuator (Heater A/C -
Manual
Fig. 17 Evaporator Location in Heater A/C Unit
(Upside Down)
(4) Install the Heater A/C unit into the vehicle.
RECIRCULATING AIR DOOR ACTUATOR
REMOVAL
(1) Remove the instrument panel (refer to Group
23, Body).
(2) Disconnect the vacuum line (Fig. 18) or electri-
cal connector (Fig. 19).
(3) Disconnect the actuating rod clip (Figs. 18 and
19).
(4) Remove the actuator retaining screws. Fig. 19 Recirculating Air Door Actuator (ATC)
(5) Remove the actuator (Fig. 18 or 19). RECIRCULATING AIR DOOR
INSTALLATION REMOVAL
(1) Position the actuator on the Heater A/C unit. (1) Remove the Heater A/C unit from the vehicle.
Install and tighten the screws. (2) Disconnect the actuating rod clip (Fig. 18 or
(2) Connect the rod and rod clip to the door lever. 19).
(3) Connect the vacuum line (Heater A/C - Manual) (3) Pry the recirculating door shaft retainer from
or the electrical connector (ATC). the shaft (Fig. 18 or 19).
(4) Install the instrument panel (refer to Group 23, (4) Remove the recirculating door through the top
Body). opening.

37. ZJ HEATING AND AIR CONDITIONING 24 - 37
INSTALLATION
(1) Install the recirculating door through the top
opening and position in place.
(2) Press the recirculating door shaft retainer onto
the shaft.
(3) Connect the rod and rod clip to the door lever.
(4) Install the Heater A/C unit into the vehicle.
TEMPERATURE / BLEND AIR DOOR MOTOR
The temperature/blend air door motor is located
under the instrument panel and can be removed from
the passenger compartment.
REMOVAL
(1) Disconnect the electrical connector (Fig. 20).
(2) Remove the retaining screws.
Fig. 21 Center Adaptor Heat Duct
(3) Remove the temperature/blend air door motor
(Fig. 20).
Fig. 20 Temperature/Blend Air Door Motor
INSTALLATION
(1) Position the motor over the door connection.
(2) Install and tighten the retaining screws.
(3) Connect the electrical connector. Fig. 22 Temperature/Blend Air Door
INSTALLATION
TEMPERATURE / BLEND AIR DOOR (1) If removed, install the door-to-motor pivot con-
nection. Position the motor and tighten the screws.
REMOVAL (2) Install the door.
(1) Remove the Heater A/C unit from the vehicle. (3) Position the top half of the Heater A/C unit
(2) Turn the Heater A/C unit upside down. onto the bottom. Be sure the door pivot pins align
(3) Remove the retaining screws holding the two with the pivot holes.
halves together. Remove the center adaptor heat duct (4) Carefully turn the Heater A/C unit over. Install
(Fig. 21) and remove the screw. and tighten the screws.
(4) Disconnect the electrical connectors. (5) Snap on the lower center air duct.
(5) Remove the bottom half of the Heater A/C unit (6) Connect the electrical connectors.
(Fig. 22). (7) Install the Heater A/C unit into the vehicle.
(6) Remove the door (Fig. 22).
(7) To replace the door-to-motor pivot connection, HEAT / DEFROST DOOR ACTUATOR
the motor must be removed. This actuator is used only on the Heater A/C (man-
ual) units.

38. 24 - 38 HEATING AND AIR CONDITIONING ZJ
1995 Grand Cherokee
Publication No. 81-370-5147
TSB 26-12-96 December, 1996
REMOVAL
(1) Remove the Heater A/C unit from the vehicle.
(2) Turn the Heater A/C unit upside down.
(3) Disconnect the vacuum line (Fig. 23).
(4) Separate the door pivot connection from the door pivot
pin (Fig. 23).
(5) Remove the retaining screws.
(6) Remove the heat/defrost door actuator (Fig. 23).
Fig. 24 Heat/Defrost Door Motor
(5) Install and tighten the two bolts that secure the center
instrument panel support bracket to the instrument panel.
(6) Install and tighten the two bolts that secure the center
instrument panel support bracket to the left side of the floor
pan transmission tunnel.
(7) Install the cluster bezel, instrument panel center bezel,
instrument panel top cover, steering column opening cover,
knee blocker, left instrument panel end cap and left lower in-
strument panel trim from the instrument panel. Refer to
Group 8E - Instrument Panel and Gauges for the procedures.
Fig. 23 Heat/Defrost Door Actuator (8) Install the upper and lower steering column shrouds
INSTALLATION onto the steering column.
(9) Connect the battery negative cable.
(1) Install the heat/defrost door actuator.
(2) Install and tighten the retaining screws.
(3) Press the door pivot connection onto the door pivot pin.
HEAT / DEFROST DOOR
(4) Connect the vacuum line.
(5) Install the Heater A/C unit into the vehicle. REMOVAL
(1) Remove the Heater A/C unit from the vehicle.
HEAT / DEFROST - PANEL / DEFROST DOOR MOTOR (2) Turn the Heater A/C unit upside down.
(3) Separate the door pivot connection from the door pivot
This motor is used only on models equipped with the op- pin.
tional Automatic Temperature Control (ATC) system. (4) Disconnect the electrical connector or the vacuum line.
(5) Remove the retaining screws holding the two halves to-
REMOVAL gether. Remove the center adaptor heat duct (Fig. 25) and re-
(1) Disconnect and isolate the battery negative cable. move the screw.
(2) Remove the three screws that secure the upper and
lower steering column shrouds to the steering column and re-
move the shrouds.
(3) Remove the cluster bezel, instrument panel center be-
zel, instrument panel top cover, steering column opening cover,
knee blocker, left instrument panel end cap and left lower in-
strument panel trim from the instrument panel. Refer to
Group 8E - Instrument Panel and Gauges for the procedures.
(4) Remove the two bolts that secure the center instrument
panel support bracket to the left side of the floor pan trans-
mission tunnel.
(5) Remove the two bolts that secure the center instrument
panel support bracket to the instrument panel.
(6) Remove the center instrument panel support bracket
from the vehicle. Fig. 25 Center Adaptor Heat Duct
(7) Unplug the wire harness connector from the motor
(Fig. 24). (6) Remove the bottom half of the Heater A/C unit.
(8) Remove the three screws that secure the motor to the (7) Remove the door (Fig. 26).
bottom of the heater-A/C housing.
(9) Remove the motor from the housing. INSTALLATION
(1) Position the door in the hole.
INSTALLATION (2) Press the door pivot connection onto the door pivot pin.
(1) Position the heat/defrost - panel/defrost door motor to (3) Position the top half of the Heater A/C unit onto the
the bottom of the heater-A/C housing. bottom. Be sure the door pivot pins align with the pivot holes.
(2) Install and tighten the three screws that secure the mo- (4) Carefully turn the Heater A/C unit over. Install and
tor to the housing. tighten the screws.
(3) Plug in the wire harness connector to the motor. (5) Snap on the lower center air duct.
(4) Position the center instrument panel support bracket to (6) Connect the electrical connectors.
the instrument panel. (7) Install the Heater A/C unit into the vehicle.

39. ZJ HEATING AND AIR CONDITIONING 24 - 39
INSTALLATION
(1) Install the panel/defrost door actuator.
(2) Install and tighten the retaining screws.
(3) Press the door pivot connection onto the door
pivot pin.
(4) Connect the vacuum line.
(5) Install the Heater A/C unit into the vehicle.
PANEL / DEFROST DOOR
REMOVAL
(1) Remove the instrument panel (refer to Group
23, Body).
(2) Remove the defrost duct (Fig. 28).
Fig. 26 Heat/Defrost Door
PANEL / DEFROST DOOR ACTUATOR
This actuator is used only on the Heater A/C (man-
ual) units.
Fig. 28 Defrost Duct
REMOVAL (3) Disconnect the actuating rod (Fig. 27 or 29).
(1) Remove the Heater A/C unit from the vehicle. (4) Pry the panel/defrost door shaft retainer from
(2) Disconnect the vacuum line (Fig. 27). the shaft (Fig. 27 or 29).
(3) Separate the door pivot connection from the (5) Remove the door through the top opening.
door pivot pin (Fig. 27).
(4) Remove the retaining screws.
(5) Remove the panel/defrost door actuator (Fig. 27).
Fig. 29 Panel/Defrost Door (ATC)
Fig. 27 Panel/Defrost Door Actuator (Heater A/C -
Manual)

40. 24 - 40 HEATING AND AIR CONDITIONING ZJ
INSTALLATION (3) Remove the sensor assembly screws from the
(1) Install the panel/defrost door through the top instrument panel bracket. Remove the sensor assem-
opening and position in place. bly.
(2) Press the door shaft retainer onto the shaft. (4) Disconnect the in-vehicle temperature sensor
(3) Connect the rod and rod clip to the door lever. from the sensor assembly (Fig. 31).
(4) Install the defrost duct.
(5) Install the instrument panel (refer to Group 23,
Body).
SOLAR SENSOR
This sensor is used only on the ATC units. It is am-
ber in color and located right of center in the defrost
grille.
REMOVAL
(1) Pop out the defrost grille (Fig. 30).
(2) Remove the solar sensor from the defrost grille
(Fig. 30).
(3) Disconnect the solar sensor connector (Fig. 30).
INSTALLATION
Fig. 31 In-Vehicle Temperature Sensor
INSTALLATION
(1) Connect the in-vehicle temperature sensor to
the sensor assembly.
(2) Install the sensor assembly to the instrument
panel bracket. Tighten the screws.
(3) Connect the aspirator tube to the sensor assem-
bly and the Heater A/C unit.
(4) Install the instrument panel (refer to Group 23,
Body).
AMBIENT AIR TEMPERATURE SENSOR
This sensor supplies information for the ATC sys-
tem only. On vehicles with overhead consoles this
Fig. 30 Solar Sensor sensor supplies information for the console.
(1) Connect the solar sensor connector. REMOVAL
(2) Install the solar sensor into the defrost grille. (1) Remove the grille.
(3) Press the defrost grille into the instrument (2) Disconnect the ambient air temperature sensor
panel. connector (Fig. 32).
(3) Remove the sensor (Fig. 32).
IN-VEHICLE TEMPERATURE SENSOR
This sensor is used only on the ATC units. INSTALLATION
(1) Install the ambient air temperature sensor.
REMOVAL (2) Connect the sensor.
(1) Remove the instrument panel (refer to Group (3) Install the grille.
23, Body).
(2) Disconnect the aspirator tube from the sensor
assembly and the Heater A/C unit (Fig. 31).

41. ZJ HEATING AND AIR CONDITIONING 24 - 41
Fig. 32 Ambient Air Temperature Sensor
DEFROSTER DUCT
REMOVAL
(1) Remove the instrument panel (refer to Group
23, Body). Fig. 34 Rear Floor Heat Duct
(2) Remove the defroster duct retaining screws.
INSTALLATION
(3) Remove the defroster duct (Fig. 33).
(1) Connect the rear floor heat duct to the center
adaptor heat duct.
(2) Install and tighten the stud nut.
(3) Position carpet over duct and onto the floor.
(4) Install the passenger side door trim (refer to
Group 23, Body).
(5) Install the passenger seat (refer to Group 23,
Body).
(6) Install the center console (refer to Group 23,
Body).
CONDENSER
Fig. 33 Defrost Duct REVIEW ALL WARNINGS AND CAUTIONS IN
INSTALLATION THIS GROUP BEFORE REMOVING the Con-
(1) Install the defroster duct. denser.
(2) Install and tighten the defroster duct retaining
CAUTION: When removing the condenser note the
screws.
location of all radiator and condenser air seals.
(3) Install the instrument panel (refer to Group 23,
These seals are used to direct air through the con-
Body). denser and radiator. They must be install in their
original locations to prevent overheating (Fig. 35).
REAR FLOOR HEAT DUCT
REMOVAL REMOVAL
(1) Remove the center console (refer to Group 23, (1) Disconnect the negative cable from the battery.
Body). (2) Recover refrigerant system into a recovery/recy-
(2) Remove the passenger seat (refer to Group 23, cle device.
Body). (3) Disconnect the A/C hoses from the condenser
(3) Remove the passenger side door trim (refer to and plug the openings.
Group 23, Body). (4) Remove the grille.
(4) Roll carpet back. (5) Remove the upper brace bolts from the two ra-
(5) Remove the stud nut (Fig. 34). diator braces (Fig. 36).
(6) Disconnect the rear floor heat duct from the (6) Remove the two crossmember-to-radiator
center adaptor heat duct (Fig. 34). mounting nuts (Fig. 36).

42. 24 - 42 HEATING AND AIR CONDITIONING ZJ
Fig. 35 Air Seals
(7) Through grille opening, remove bolt securing (8) The radiator upper crossmember (Fig. 37) can
lower part of hood latch support to lower frame cross- be adjusted left or right through the use of slotted
member. holes. Before removal, mark the original position of
the crossmember.
(9) Remove the remaining bolts securing the radi-
ator upper crossmember to the body. Do not remove
the hood latch or hood latch cable from the cross-
member. Lift the crossmember straight up and lay to
the side (Fig. 37).
(10) Remove the four lower condenser attaching
bolts.
(11) Remove the two upper condenser attaching
bolts (Fig. 37).
(12) Carefully remove the condenser from the vehi-
cle.
INSTALLATION
Add 1 ounce of refrigerant oil into the condenser if
it is replaced.
(1) Carefully position the condenser into the vehi-
cle.
(2) Install and tighten the two upper condenser at-
taching bolts.
(3) Install and tighten the four lower condenser at-
taching bolts.
(4) Align the radiator upper crossmember with the
Fig. 36 Radiator—A/C Condenser Mounting
scribe marks. Install and tighten the radiator upper
crossmember bolts to the body.

43. ZJ HEATING AND AIR CONDITIONING 24 - 43
Fig. 37 Radiator Upper Crossmember—Typical
(5) Install and tighten the radiator upper cross-
member mounting nuts.
(6) Through grille opening, install and tighten bolt
securing lower part of hood latch support to lower
frame crossmember.
Fig. 38 Accumulator and Bracket
(7) Install and tighten the two upper bolts holding
the radiator brace to the upper radiator crossmem- LIQUID LINE
ber. The fixed orifice tube is located in the liquid line
(8) Install the grille. near the condenser. The orifice has a filter screens on
(9) Remove the plugs from the openings. Connect the inlet and outlet ends of the tube body. If the fixed
the A/C hoses to the condenser. orifice tube is plugged, the liquid line must be re-
(10) Connect the negative cable to the battery. placed.
(11) Evacuate and charge system.
REMOVAL
(1) Disconnect the negative cable from the battery.
ACCUMULATOR
(2) Recover the refrigerant system into a recovery/
REMOVAL recycle device.
(3) Disconnect the quick-connect fittings at the
(1) Disconnect the negative cable from the battery.
evaporator and the condenser.
(2) Recover refrigerant system into a recovery/recy-
(4) Remove the liquid line.
cle device.
(3) Disconnect hoses from the compressor and INSTALLATION
evaporator. Plug the openings. (1) Install the liquid line.
(4) Unplug the harness from the low pressure (2) Connect the quick-connect fittings at the evap-
switch (Fig. 38). orator and the condenser.
(5) Loosen the support bracket screw (Fig. 38). (3) Connect the negative cable to the battery.
(6) Remove the accumulator. (4) Evacuate and charge the system.
INSTALLATION DISCHARGE LINE
Add 4 ounce of refrigerant oil into the accumulator
if it is replaced. REMOVAL
(1) Install the accumulator in the support bracket (1) Disconnect the negative cable from the battery.
and tighten the screw. (2) Recover the A/C system into a recovery/recycle
(2) Plug the harness into the low pressure switch. device.
(3) Remove the plugs from hoses. Install new (3) Disconnect the quick-connect fitting at the con-
o-rings and connect the hoses. denser.
(4) Connect the negative cable to the battery. (4) Remove the discharge line-to-compressor mani-
(5) Evacuate and charge the system. fold bolt. Discard the O-ring.
INSTALLATION
(1) Install new O-rings and install the discharge

44. 24 - 44 HEATING AND AIR CONDITIONING ZJ
line-to-compressor manifold.
(2) Connect the quick-connect fitting at the con-
denser.
(3) Connect the negative cable to the battery.
(4) Evacuate and charge the system.
HIGH PRESSURE CUT-OUT SWITCH
The high pressure cut-out switch is located on the
discharge line connection at the compressor manifold.
REMOVAL
(1) Disconnect the negative cable from the battery.
(2) Remove the connector from the switch.
(3) Unscrew the switch.
INSTALLATION
(1) Install and tighten the switch.
(2) Install the connector onto the switch.
(3) Connect the negative cable to the battery.
VACUUM RESERVOIR
The vacuum reservoir is located under the battery
tray. Fig. 39 Vacuum Reservoir
REMOVAL INSTALLATION
(1) Remove the battery (refer to Group 8B, Bat- (1) Position the vacuum reservoir to the battery
tery/Starter/Generator Service). tray. Install and tighten the vacuum reservoir
(2) Disconnect the vacuum hose (Fig. 39). screws.
(3) Remove the battery tray and vacuum reservoir (2) Install the battery tray and vacuum reservoir
assembly (refer to Group 8B, Battery/Starter/Genera- assembly (refer to Group 8B, Battery/Starter/Genera-
tor Service). tor Service).
(4) Remove the reservoir attaching screws (Fig. (3) Connect the vacuum hose.
39). Remove the vacuum reservoir from the battery (4) Install the battery (refer to Group 8B, Battery/
tray. Starter/Generator Service).
TORQUE SPECIFICATIONS
AIR CONDITIONING COMPRESSOR Manifold Bolts .............................25 N⅐m (19 ft. lbs.)
Shaft Bolt ..................................13 N⅐m (115 in. lbs.)
DESCRIPTION ................................................TORQUE
Compressor
Mounting Bolts ............................27 N⅐m (20 ft. lbs.)