Do you have any mods done-- or have a tuner-? You should fill out your signature with the info-- that will help. [User CP center top bar]
Take the under hood fuse box cover off and inspect the wires under the fuses. Sometimes mice make a next there and cut up the wires-- then they short.
Chevy 04.5 LLY, 2X, shell, XDR, MikeL Heavy duty up-grade, 6spd, TransGo, deep pan, de-badged, 65 Gallon replacement Aero tank, LBZ-mp, Kennedy pump, shimmed, Pre-fuel filter, tow mirrors, BU cam, gauges, GPS, Sirius, bags, custom grille, fender vents, HD trans cooler- Curt front hitch, footwell lights, load lights, Studs, head gaskets.