Today was the first truly hot day we've had so far this year so I was partaking of the comforts of the air conditioning in my S on the way home from work. I stopped at home and picked up my wife and we went out for dinner. All this time the A/C is performing marvelously. Then, when we leave the restaurant to head home, nothing. Pressing the A/C button lights up the switch and nothing else. The compressor doesn't kick on, we sweat on the way home.

I get home, let the car cool down so I can have a look under the hood. First things first, I check the fuses.

It's not the fuse.

I press the A/C switch and visually check the compressor as the engine is running.

The A/C clutch isn't engaging. OK, we're getting somewhere at least.

I push the defrost button too, maybe it's a bad A/C switch. Nope.

I inspect the receiver/dryer behind the driver's side headlight. Yep, there's a sight glass there. Damned if I know how to tell if it's good or bad, though.

I have a look at the wiring for the compressor. Bingo! I jiggle the connector and the clutch engages and the compressor starts making magic cold air.

Then I notice something strange:





So I trace the black wire back to (what I assume is) the low pressure cutoff switch. Hmm. Looks like something's up here, too:





So my question is this: what's going on here? Does the cut wire go to the AC compressor? Did a PO jumper the low-pressure cutoff switch? Should I reconnect the wire and plug in the loose connector near the switch and see what happens? It doesn't look stock to me, but I figured I'd ask the experts. The A/C system has worked flawlessly for the year I've owned the car, and it was converted to R134a at some point by a PO, at least according to the sticker on the fuse box.

 

Looks like he may have re-routed a power lead to the compressor. I don't think that he jumped out the low pressure switch, because the old connector looks pretty funky. Can't tell more until you get a meter involved, or at least a test light. If you get compressor engagement/disengagement when you wiggle the wire, check it out for a break, or open. You'll also have to open up the loom, if you want to investigate further.