Vehicle is a 02 bravada. At idle I can see the pulley or clutch on front of the ac compressor(SERPENTINE BELT ATTACHES) not really spinning but attempting to on its own. It will move a bit but not much. When I turn the ac on, its cold and this pulley will move. Could a bearing be going bad inside the pulley? If so, is it time to replace the compressor? Anyway to check it or clean it or any suggestions? It is making a gawd awful noise. Thanks