Serpentine Belt Issue

Hi, I have an 04 Deville with roughly 60,000 miles. Last night I went out and I noticed that the serpentine belt was squealing when I slowed down. I also noticed that the headlights dimmed slightly and the steering got a little more firmer, which I know is sign of the belt not spining as it should. It was raining like crazy all day yesterday and there was alot of ponding on the street. I noticed that it did not do it today and it was dry out today. Does anyone know if there is are any parts that are prone to going on this model (belt, tensioner, etc). My guess is that it was the moisture, but I am just looking for some input. Thanks

Like you said, belts wear, tensioners get weak and even stick, not allowing proper belt tension. Check and make sure all your splash shields are in place under the vehicle and inside the wheel wells.