Chevrolet Repair Questions? Ask a Mechanic for Answers ASAP
I am sorry your having this problem
can you remove and clean both battery cables with sand paper or a scotch pad and see if the power will come back ?
if not on the passenger side front of the lower engine block there is a battery cable ground to the engine near the balancer can you be sure all those grounds there are clean and tight ?
with from what you are describing this truck is missing the main power or ground from a bad battery connections or the ground on the engine block