'78 E350 chassis, high low beams don't work, lights flicker

[bolivier]

So I have a '78 E350 Chassis MH as stated. Here's the deal. The floor, high/low beam switch doesn't do anything. Also, after the headlights have been on for around 30 minutes they start to go on and off randomly. Not cool. My first thought was replace the high/low beam floor switch. Kill two birds with one stone kinda thing. No luck. While I was down there I noticed the wires that go to the floor switch were pretty hot, while the headlights had only been on less than 5 minutes. Heat was what I first thought of when the headlights started going on and off. Any ideas?

Thanks,
Brent

[j-d]

As PJ2 mentioned, there's a breaker in the headlight switch. Running/Park/Dash lights are fused. When I first read this I thought Loose or Bad Ground, but now I'm thinking more like Pinched or Chafed Wiring Harness.
Suggest a good visual inspection. Concentrate on where work has been done, repairs or modifications made, and items added by owner(s) or the coach builder.
Chassis builders (Ford in this case) do a pretty good job of protecting original wiring. Others aren't always as careful.

[PaulJ2]

Sounds like the circuit breaker in the headlight switch is doing what it is supposed to do-- trip under a too heavy load. Maybe something causing the high and low beams to be on at the same time. Bad bulb? Bad dimmer switch?

[spacedoutbob]

Sounds like you have a bad headlight switch.

Bob in Calif.