s 10 trucks usually have a ground on both sides of the frame near the end with possibly a splice pack thats usually on the pass. side rail.if you have a ground problem electricity will search for one and cause strange things to happen.clean the frame rail on both side and aplly dielectric grease to the grounds and clean and retighten themI found the wire on the harness. I don't have a clue where it was supposed to be grounded from the factory. I couldn't find anything. I just ran it back to the drivers side frame rail where my other ground is. The wiring schematic said "passenger side frame rail".