'85 300D A/C question
 

I have my car with a shop where a distant family member works getting the A/C working. I thought all it needed was an avac. done and the conversion to 134. When I bought the car 2 1/2 years ago the PO said the system was worked on the previous summer and it was too cold to check when I took it home.

Anyway...my mechanic says I need a new compressor clutch and he can't find one. My question is this--do I have to go to a dealer? I checked FastLane. Also, is there something that he can do to test the clutch that he may not know? I know the clutch spins freely, but am not sure if it ever engaged.
Thanks, and BTW, I did search and did not find an answer to my questions.

It's a Delco R4 compressor - made by GM and used by GM on several 10s of millions of vehicles. Should be common as dirt. The entire compressor can be had new for $250 or so. Try calling some chain stores looking for a clutch.