I also just got an 85 300D with a missing AC compressor belt. I tried rotating the compressor (the triangle thing) and it wasn't frozen, so I put a belt on it yesterday. No noise, so the bearing is fine. The clutch never engages, so now I'm waiting for a gauge set and a couple other things to check the charge. If there is no charge, I will pull a vaccuum and see if anything is leaking. I'll fix any leaks I find, then replace the receiver/dryer and expansion valve, flush, and recharge. If there is already a charge, then maybe the low pressure switch is defective, if not I'll have to go looking for some other electrical issue, maybe the compressor clutch coil. I suppose what I can do before my new AC tools arrive is test the clutch to see if it is shorted or open.

Brian Keese
85 300D
81 Isuzu Pup running WVO