- The A/C on my '94 GP (3.1L) suddenly stopped working about two weeks ago. Finally got around to trying to figure out the problem yesterday but didn't get very far. Here is what I did.
The compressor does not come on. At least I don't think it does. I am not 100% sure of what I am looking for because I never did this before, but staring the compressor when I have my son press the A/C button on the dash does absoulutely nothing. (The light does light on the button however). My understanding is that there should be an audible "click" when the compressor engages and something should start "rotating" on the compressor. (There was no click and nothing started rotatiing when he engaged the A/C that wasn't already rotating.)
So based on some info I was told:
#1- Assumed it was low on R134 which was preventing the compressor from coming on. I picked up a "recharge can" at Advanced Auto Parts. The can comes with a color gauge on the hose. The hose can be removed from the can itself and a pressure reading can be done with it connected or disconnected from the can. So following the directions on the can, I placed the guage on the "low" pressure side (fatter tube), started the engine and turned the A/c on Max Cool. The gauge didn't move. A-ha! so my ace t/s skills were correct! I connected the can to the hose and pressed the top of the can and heard the refridgerant leaving the can. In about 8 seconds the guage jumped from nothing to "full". Thought it was suspicious that the can still seemed full- but what do I know? But wait a minute- the compressor still isn't running? Turned the A/C off and back on again - still nothing.
None of the line feel cool and I assume that is because the compressor isn't running, right? I checked fuses and they appear OK. I found the compressor relay in the box near the firewall- should I try replacing that? What is the low pressure switch and where is it?
I am not the greatest "mechanic" but I can follow directions if anyone has a moment to offer some suggestions- thanks!