[speeddemon31176]

Do your brake lights on your truck stop working then also? If so then I would say that the switch may be grounding itself out some how or you have a short in the wiring somewhere.

 

[speeddemon31176]

Very possible. Try and unplug it from the harness in the back at the frame rail and try again. If that is it the you only have to replace the 7 pin plug assembly.

 

[speeddemon31176]

Window&door has a good idea there with a possible bad brake controller. I would also climb under the dash and see if you have chaffed wires that could be shorting out the brake circuit.