Strange "whining" Noise coming from fan/belt area

I parked at home not hearing a thing. I go to turn the truck on 5 minutes later and I hear a whining/high pitched humming noise coming from the belt and fan area. I don't know if it's the belt but it seems ok when I checked it out. Seemed to get louder when I drove this morning. Also got a dead battery. Don't know of that's a coincidence or ties into relation. Anyone have the same problem in the past?

 

Your alternator probably went out. Have it checked at AutoZone or your local parts place.

 

Alternator. I've always found a local electrical shop to do a rebuild is a better value than a OTC parts house mass reman bit.

 

Pull the belt off and spin all of the idler pulleys and accessory pulleys.