not odd behavior at all Troy, quite normal on an old truck, for the same reason you cleaned up the lights and their immediate mounting, you need to tend to the rest of the circuit - the bed 'sitting' on the frame is a real poor ground ... even where the bolts go thru is poor after a few years of slow galvanic corrosion building up - may look ok, but electricity ain't fooled
it's always a good idea to have a wire, well connected to cleaned spots, between the bed and the frame - same for the cab and the frame - as Brendan sez, the ground is critical to the proper flow of things
Bill
