[usafracer]

I see you live in Why not Minot LOL. More than likely you run your truck on defrost a lot and that will cause your a/c compressor to cycle to help remove excess moisture from the air in the cab. The chirp you hear is the belt slipping every time the compressor kicks on.

As mentioned a quality belt like the Goodyear gatorback should cure your problem. While you have the belt off don't forget to look over all the other accessories to make sure they are in good working order.