Either wiring, grounds, sealed beams, or dimmer switch, easy to troubleshoot

Pull out the dimmer, you have three wires.

One is hot with headlight switch on.

Dimmer routes power to either hi or low circuit, so you should be able to "jumper" from the hot to either side and see what happens. You get lights, it's the switch, you don't , it's.....


wiring, grounds, or sealed beams

So go up front, pull the lamps, wiggle the connectors, and get your ohmeter, check the hi--beams for continuity with your meter. Clean and retighten the wiring harness grounds.

Even with a nagging girlfriend, a sixpack, and the dog barking, this should not take you an hour to fix