Having trouble with my A/C on my 82. I had a bad monovalve diaphram which has been replaced. Also had a broken A/C belt which has been replaced.

Symptoms: Air blows slightly cool (cooler than ambient) most of the time, sometimes it only blows warm air.

Checked so far:
1) A/C clutch relay clicks and clutch engages.
2) Shorted Aux fan leads and fan comes on, but otherwise fan does not come on. Likely bad temp switch for Aux fan?? I drove aroudn the block with the leads shorted and fan running, but didn't seem to be any cooler out of the vents.
3) Checked for voltage at pressure switch on rcvr-drier, have voltage on both leads. I checked the voltage with the leads attached to the switch. This is what the CD Shop Manual says for voltage at both leads (12v): "If both plugs of pressure switch are carrying voltage, a fault on coil of electromagnetic clutch or on electric line between pressure switch and clutch coil is indicated (83-508)". I'm not sure what this means, but it seems this may be my problem.
4) I checked the sight glass on the rcvr-drier, and I could not tell if refrigerant was flowing or not. If it is, it appears to be dark grey in color.

So, my initial thought was low refrigerant and possibly a bad temp switch, but now with the note on the voltage, possibly something else?

Thanks for your inputs...

If your compressor is engaging then number 3 does not apply to you...

Does your system have R12 ?

The site glass is one of those things where sometimes it is useful and sometimes not...

Yes, I have R-12.

Since you have done these checks and found what you did... you are probably going to have to put guages on it to tell anything more definitive...
How long have you had the car ?
Has any AC work been done on it while you owned it ?
Did it work fine at one time ? How long ago ?
Was the change from ok to this slow or fast ?
Have you cleaned your condensor and radiator fins...and straightened them ?

I'm thinking I will likely take it in tomorrow, I don't have guages, and think I've taken it about as far as I'd like. I do have a good shop to goto, so should not get ripped.

OK, it is nice to have a shop you trust... AC work is not fun...

Needs a new compressor, line and rcvr/drier. Was leaking from front of compressor. Cost quoted was $920

Other issue is that some PO bonehead added R134 to the R-12, so it had BOTH refrigerants in the system!!

They will let me use my own parts, and I'm guessing I can save $ buying them from Phil.

So, now my question is do I take the A/C course online so I can buy R-12 and do it myself (along with buying the tools), or do I have the shop do it?

I'm not sure what a compressor costs, Phil is gone til Monday and the compressor doesn't show up online.

These people are right in your area; they answer questions, and are reliable:
http://www.ackits.com/merchant2/merchant.mvc?Screen=PROD&Store_Code=AMA&Product_Code=15-20206

__________________
The Golden Rule

1984 300SD (bought new, sold it in 1988, bought it back 13 yrs. later)

Thanks, will likely buy from them and have my shop do the install. Half of the $920 quote was for the compressor, so $207 for a new one is a great buy. The owner at the shop says he won't install a reman compressor, has had too many problems.

So, looks like it will end up costing around $600-$650 total to have my mechanic do the work.