Was out driving around today and heard some belt squealing. Parked and popped the hood and saw the compressor clutch engaging and stopping/belt squealing, so my guess would be the compressor probably sat too long and is no longer any good. Never used the A/C or even tried it when I first got the truck and havn't inquired with my brother, the previous owner, if it ever worked.
Just went out and applied 12vdc to the compressor, seems to engage and disengage fine. No funny noises when spun by hand. I"m sure I had the belt tight enough, hmmm, maybe I better check the tensioner pulley, didn't do that. <img src="/forums/images/graemlins/rolleyes.gif" alt="" />