there are two serpentine belts in my car - One is solely for the alternator, and one is for the power steering, air conditioning, water pump, etc.
Just replaced both serpentine belts in my car, was not running into any kind of squealing before, but had not replaced the belts yet and the car was up to 90k miles. After replacing the belts, they started squealing.
Right now, the belts on my car will squeal if I turn on both my headlights and the air conditioning or heat in my car, usually when I come to a stop and idle, or slow down a bit.
Just having the headlights on, alone, doesn't seem to impact anything, and simply turning the steering wheel while idle or driving doesn't seem to set it off, either.
Additionally, running the stereo fairly loud seems to bring on a bout of squealing from the belts until I turn it off.
I am getting the impression this is due to load on the alternator, but the tensioner pulley (which is my immediate thought of what would be causing this slipping and squealing noise) is for the other belt, the one that connects the power steering and such.
If I keep the load on the alternator low, I never hear squealing.
But if I turn on my headlights along with the stereo, turn on the fans in the car for air conditioning or heat, I start hearing the belt(s) squeal until I turn such things off.
Anyways, there is no tensioner between the alternator and the motor, it's just one belt that connects the two with nothing in between - at seemingly a static distance. It's installed by removing the bolts on the alternator so it can be moved into and out of place.
That said, I'm not sure of anything I could do to change the tension on this belt, so I'm not certain what to do to resolve the squealing.
The belt I replaced the original with was a bit cheap, could it just be a low quality belt?
EDIT: It appears that I need to tighten the tension on the alternator belt using the Adjusting bolt; I found a diagram that more accurately represents this setup (below)
(Vehicle: 2007 Chrysler PT Cruiser)