Belt? squeals when cold. it goes away once it warms up. how do I tell if its the belt or water pump bearing?

The belt is a couple or three years old but upon a closer inspection it turns out the belt was too loose. so I tightened the bolt on the tensior pully a bit and the belt tighten right up but.... I would say too much. What does that bolt do? I cant seem to get the belt to back off. does it directly tighten the belt?

A belt squeal is normally worse when cold. how long has it been since its been replaced? look at the ribs of the belt to see if you see any cracks in it, like a dry-rot. if its cracking, replace it. also if the belt tensioner is getting weak the lack of tension can cause the belt to slip and squeal. try replacing the belt and while its off spin all the pulleys by hand. when the belt is off is a good time to see if any of the other pulleys bearings are going bad. a good pulley will be silent, a bad one will squeak or make a grating sound. but the squeal while cold is probably just the belt itself.

Hi
Spray the belt with wd40 if it goes quiet then it will be the belt, It may just need to be tightened as they often do after a cold spell, the metal contracts are expands in cold/hot climates.

Have the car running and spray directly onto the altenator and the belt.

If it is still squelling then get the pump checked out.

Hope this helps
Regards
Dan