It'll be interesting to see if anything changes after following Bill's instructions. I'd still verify the gauge of wiring used. When the wiring was replaced by the previous owner, did he include the terminal block on the left fender?
If cleaning the terminals and connections and/or dimmer switch replacement doesn't fix the problem, I would install new 12 ga wires to headlights with the terminal block. It's pretty easy to do.
Hi Otto,
The truck has a new wiring harness and terminal blocks but the dimmer switch appears to be old.
Kevin
