97 Suburban Intermittent A/C problem

Hello,

Right now my compressor will not engage therefore I have hot air coming out of the vents. This scenario comes/goes randomly. Everything may work fine the next time I start-up and try the A/C and I may not experience the problem for 6 mos. I had a mechanic check it out and of course there was now problem during the checkout. The system is fully charged, no leaks and this certainly appears to be a electrical issue, he had mentioned to check a switch next time it happened, but I can't recall which one it was several months ago. Does anyone have a wiring diagram they can share or opinions on where to start troubleshooting?

Thanks,

Shawn

There is a low pressure limit switch which won't let the compressor run unless there is sufficiant freon in the system, its on the pass side by the drier, its attached to the a/c lines and has a plug with 2 wires, next time the a/c fails, unplug the switch and jumper the plug with a paper clip. If the compressor starts running, the switch could be bad or you have low freon.

Jeff

I have a 99 Suburban with the same symptom except it happens a little more frequently. I checked it out today and bypassed all related pressure switches and determined that I have power to the clutch but the clutch is not engaging. I believe it may be the clutch itself. Is yours still having a problem??