Please bear with me as this is my first A/C troubleshooting experience. After finding that the a/c in my newly purchased 90 740GL was not working, i've decided to see if I can identify the problem. These questions might seem simple, but I really have no idea where to start. First, the compressor is the thing underneath the alternator with a belt connected to it, correct? If so, when i engage the a/c, the clutch on the end of the compressor is not engaging. Is that how it's supposed to work? I was told that the pulley on the end of the compressor spins idly while the a/c is off. When the a/c is turned on, the clutch on the end of the compressor pushes the disc on to the pulley, which then turns with it, supplying energy to the compressor. Is that how it works, or am I completely off base? Also, does the air outside have to be a specific temp. or greater for the a/c to run? When i was testing this out, it was 65F.