How To Buy An AC Compressor made easy. Buying auto parts can be difficult, but it doesn't have to be. This guide explains how easy it can be to find the right replacement air conditioning compressor for your vehicle. You do not have to buy from your mechanic or your dealer, you can purchase the ac compressor yourself at a fraction of the cost. Just follow the steps in the presentation and you we know how to buy an ac compressor in no time!