Cruise Control Problems

I have a 96 Chevrolet Truck..If I knew where to start on fixing my cruise control.. The Manual I have never mentions it and only shows it in a diagram.. So I don't know if ti's vacuum related or electronic, how to fix or diagnose..??? It quit working a week ago.. If I turn it on and set it it doesn't grab and something in the dash makes a clicking noise when I turn the cruise off it makes a springy noise from under the dash? What could be the problem? Please help...