A/C problem - Clutch not engaging on compressor

[Thunderscreech]

A few days ago, my A/C suddenly stopped working. No gradual dropoff, it just produced uncooled air when I started my car and hasn't recovered. Things I have done:1. Checked fuse under dash (which was holy hell to get at) and it's fine. I verified that removing it makes the A/C switch no longer illuminate, so that's a troubleshooting step to consider for the future.2. Checked the vent door (accessible via the front passenger side under the dash) and verified that it's properly positioned and moves when I alter the temp knob.3. Checked fuses under the hood, didn't find an A/C one specifically but they all appear intact at quick glance.4. Checked system pressure (under the assumption that perhaps a low-press sensor cut off the system) while running w/ A/C on and it came up green (color coded checker, not PSI so no #s)5. Observed the compressor while turning A/C on and off and noticed something important: The clutch is not engaging.My expectation is that the end of the pulley that the serpentine belt goes through would start moving when I turn on A/C, but it remains motionless. I can spin it freely, it doesn't appear to be binding.What are some likely failure points, and what do y'all suggest I check next? I'm thinking the clutch relay is a possibility, I haven't figured out how to safely bypass it yet to energize the clutch manually, but that's mostly because that damn plug just won't come off. Ideas?

[djkeev]

what year?what engine and transmission?Dave

[Thunderscreech]

2003 2WD automatic w/ the 1.8L 16v straight 4.

[Thunderscreech]

Ok, shop checked it out and offered the diagnosis that the A/C clutch has failed. They then quoted me $900 to fix it, probably more now to cover the line of burnt rubber I left in their parking lot scooting out of there. Nice folks, but that's just a little bit too much. Their price included:- A preventative replacement of the A/C clutch relay (if it's not busted or located in a wacky location, why the heck would you replace it?)- A vacuum and refill of the 134a (why would you need to crack this open while replacing a clutch? They say it's 'just in case' it's empty, to which I note that the failure was very sudden, so... no.)- New A/C clutch (this is reasonable, if that's the broken part, heh)My plan is currently to plumb the archives here to see if I can find out just how hard it is to do myself. If I can get my bear-like hands down in there to loosen the compressor & go through the various dances and incantations to replace the clutch without letting the magic freon out, then perhaps I will. Zoinks, it was 84 out today. What kind of Fall IS this, anyhow? Oh, right, tomorrow's the magic day.