Serpentine belt replacement a ton of great posts

Does it run the AC compressor? If so, it has a tensionier the same as the other belt. Refer to the belt routing diagrams for locations. However, if you are starting the engine without the AC on, I doubt that is the problem unless the belt is really loose.

Let me know what you find. Here is the address for the belt routing diagram you need.

https://www.2carpros.com/diagrams/chevrolet/silverado/2001

Joe