Power steering type squeal

Hi there everyone. My 98 4x4 has slight low pitched squeal once it warms up a bit and then sticks around when idling. The sound is a bit like when really cranking on the power steering or if it low in PS fluid, however I am doubtful it is the PS pump. When idling and steering is straight, if I roll up the power window, the noise increases when the window gets all the way up if I hold the window button up. This causes me to think it is something to do with the electrical charging system. Thank you in advance for any advise you provide.

 

Pull each belt one at a time while running the engine for a few seconds after each belt is pulled. That'll tell you what external drive component it is when the noise goes away.. Unless its internal.