1998 Cadillac Deville Chirping from belts

Other Category problem
1998 Cadillac Deville V8 Front Wheel Drive Automatic 120k miles

I recently had an alternator go bad and had it changed. Immediatly afterward the alternator belt begin chirping especially loud on start up and slowly gets quiter. After the altenator change I also began to get a loud rattling sound whenever I turned on the air or heat. I tried to change the belt on the altenator but it only got better for a day or so. Should the Tensioner be my next task and what about the other rattling?