99 Peterbilt No headlights

Don't know what type truck you have, but I've seen several with broken wires in the harness where the hood hinges, after alot of bending they sometimes break. You can unplug the wire at the switch and unplug one of the headlights and take a continuity tester and see if you have continuity (you may have to cut a long piece of wire to use as a jumper), if not then run a new wire from the switch to the headlights. If you do have continuity, then I would check the dimmer switch, which can do this also. Good luck.

 

I had a similiar problem and it was the high/low beam switch on the floor but it was a 79 KW.

 

I had sort of the same problem on my 2002. I had low beams but no high beams. After cleaning grounds, I found that the scews on the breakers in the fuse box had corrosion on them and the scews had viberated loose, so after a little brake clean and a stubbie pillips scew driver probem fixed

 

Sorry for the delay, the dimmer switch that I was talking about is made in with your turn signal, all one unit and known to go out from time to time. It's easy to change if that is the problem, just a clamp and disconnect plug.Good luck

 

This is the turn signal switch I was referring to, sorry for the mix-up.