My '92 has a lot of AC problems...I just bought it from some guy in Alabama and had it shipped up her to MD. Well, he told me he had a new AC Compressor with refrigerent installed. There is a new AC Compressor, but it is all messed up. By messed up I mean, the compressor turns on and off for no reason, the radiator cooling fan runs ALL the time, there is a constant hissing sound coming from the AC controls in the dash, the air will ONLY blow out of the top of the dash (where defrost vents are) no matter what setting the controls are set to. Do you think I can fix this myself? Or am I going to have to take it to a GM dealer and be charged a fortune? Help me out fellas!

 

Turns on & off = no (or very low) Freon

Hissing sound in dash = vacuum line disconnected

Air only comes out the top = vacuum line under dash disconnected (all the little doors that route where the air goes are controlled by little vacuum diaphragms that get vacuum sent to them by the control head; and their rest position, i.e. with no vacuum being fed to any of them, is to route it all to the defroster)

Cooling fan on all the time = normal when the A/C is on; if it does it when the system is off, then somebody has hacked the wiring

You can easily fix all this yourself if you'll take the time to learn how it works. In no case would taking it to the dealer be the right thing to do.

 

If someone did hack the wiring to keep the AC on all the time, I'd be careful after you fix it and make sure the fan turns on when the temp sensor hits 220 or whatever it's supposed to turn on at. Otherwise, you'll be overheating all over the place; some people like the cheap way out of a failed temp sensor for the coolant fan by keeping the fan on constantly.