Replace the tensioner. Stop it from getting wet by making some sort of shield to prevent water from getting to the belt.
it could be a serpentine belt or accessory belt.
Change the belt
Check you serpentine drive belt and pulleys.
serpentine belt loose
A worn belt will cause a squealing noise. The squealing noise is caused when the belt slips. Tightening the belt will temporarily fix the problem.
Worn serpentine belt and/or belt tensioner.
sounds like you need to replace the serpentine belt
Either it's too loose or you need a new belt.
Possibly the wrong belt was installed or most likely your belt tensioner is bad.
how do you change the serpentine belt on a 2001 Rodeo
how do i lossen the belt tensioner on a 2001 Hyundai Sante fe to replace the serpentine belt
Your serpentine belt is loose or worn.