Other than me taking this as the Lord wanted me to pull over into a rest area that was conveniently 2 miles ahead, as dusk had fallen tonight in NM, I noticed my headlights (also hi beams) are non-functional. Running lights are working. Where are the breakers for this? Are they in the main bay behind that fiberglass panel that has the 3 wing nuts on it? I did not see any breakers behind the panel in front of the co pilots seat, just relays.
Dave
Many of the components behind the copilot panel are self resetting CBs, not relays. I'm not at home so can't look at the wiring diagram to track down the CB for the headlights.
Rich
Dave if not the circuit breaker you have the dimmer switch and headlight switch to trouble shoot. Jim.
Headlights and high beams appear to be on 2 different resettable breakers. In a U320, headlights #39, high beams #9; high beams also have a relay, R10. All should be in front of the passenger seat.

It might be slightly different in a U270, but hopefully they kept the component designators the same.