Truck Trailer Lights Not Working. I am working with one light right now to test. There was corrosion in the connectors.and it seem to work only when I tied.
There could be a burned out bulb, corrosion, broken wires or even a There's an inadequate ground on the truck or trailer side or an overloaded harness because of too many lights. I hooked it up to my dad's truck and everything works great. I know the trailer lights on trailer are functional so it's my truck.
I ran a ground from one of the mounting bolts to one of the bolts on the trailer jack.
I know the trailer lights work fine (hooked up to a buddy's truck).
I was using the trailer last fall and the lights were working fine when I put it away. Need to be set to allow it to work? All the other signals are functioning properly.