I could certainly use some assistance to find the gremlin that have gotten into my AC unit. For some reaons it is not working - althought is ran OK last year. I can't figure out where the system has ceased to function. I turn on the AC switch and there's no light and the compressor is not engaged. I've spend hours reviewing many previous forum posts in hopes of troubleshooting this. I'm coming up empty at this point.

Here's what I've checked/done:

1. Turned the climate switch to defrost setting - no ac compressor.
2. Fuse for the AC - intact
3. Power to the AC switch - present (removed wires from back and tested)
4. Jumpered the AC relay (behind glove box)between terminals 30 to 87 - no response
5. Jumpered the lower pressure switch by firewall - no compressor(tested the switch, it was closed)
6. Ran 12v from battery directly to the AC compressor clutch - AC clutch engaged (yeah!).
7. AC system pressure ran from 25-45 lbs from doing above (normal range).


The AC light will go on momentarily if I disconect the battery, reconnect and then start the car up. It goes out in about 2-4 seconds-still no compressor. I was thinking there might be an AC system check going on.

Question:
There is another pressure switch inline before the low pressure ac fill point by the headlight. It has 3 wires. Any guesses what should be going on there?

This one has me stumped!!! Thanks to all of you in advance!

Jay