I bought a HO alternator for my project and experienced alot of squealing from the V belt. Wrote the distrubutor and he suggested replacing the belts and REALLY tightening it up. Since the belts were new, I just tigtened it further and it eliminated the squeal. Since yours is a single belt system with tensioners, I would think that the tensioner would be the culprit like Jim said. If you dont find a bad bearing, replace the tensioner and hopefully that will add the pressure you need to end the squealing. Jeep had a problem with A/C compressors kicking in and squealing so check that if its so equipped. Maybe your compressor clutch is going bad. <img src="/forums/images/graemlins/notooth.gif" alt="" />