Hey Journeydog. I took the serpentine off, and sure enough it was the pulley for the air compressor. I went to used parts junkyard and they had one, so dropped 100 bucks for it, went back and released pressure on old one, changed it out, vacuumed the new one, charged it, good to go! I had a fellow mechanic help on the charging and all that. Got that job done for just a little over a hundred bucks. Not bad.