What exactly does it do? Should it turn of the compressor if the pressure is too high, or does it simply turn on the fans at a certain pressure?<br><br>My reason for asking:<br>Cruising around friday night, the DIC shows that the alternator is not charging. By the time i hit the buttons to check the voltage, it's charging normally and I haven't had and problems with it since. <br>Didn't think much of it, till......I notice a bunch of oil spots under the car sunday. Found the A/C belt was shredded and figured the compressor was shot and coughed up all its oil. Cleaned up under the car and not a drop of oil since (dip stick level is good and has not changed either). <br><br>I installed a new belt tuesday and everything seemed to run perfectly for the few minutes I ran the A/C. No noises, clutch working properly, cold air and no more oil leaks. So I check for codes and bring up 622 and 651. There was no CEL, so this happened only one time. Reset the codes and they haven't come back all week. One of the codes has to do with 5V that goes to the A/C pressure switch.<br><br>I've heard that some (all?) compressors have a pressure relief. Could it be that while the A/C was on friday, the switch wasn't getting power and couldn't turn on the fans resulting in the compressor dumping some oil/134A to keep from blowing to smitherinies?<br><br>I'm picking up a set of gauges and will check the pressure this weekend.<br><br>Thanks<br>Tony