Noise from turning on the air conditioner

I thought it was a fan belt, but when I use the air in my truck, it sounds like I have a bird chirping loudly in the engine. It has done this for years now. but lately more than ever. Because it would go away for a long time, I have done nothing.

Farah, Please Introduce Your Truck. What’s The Make, Model, Year, Miles?

This sounds like a classic problem. However, some problems are vehicle specific.