Ghost lighting problem

[Jon Giovani]

So on a couple of early morning and late night trips I have had issues with my headlights mysteriously turning off and my dash lights going off and coming back on 30 to 60 seconds later, tells me it is an automatic reset circuit breaker. After doing an extensive search the only other similar post I could find was one on an FMTV that was having same issue. I have a 1985 AM General M925. Has anybody experienced same issue with this rig and found the root problem?
I've checked grounds and have not found any noticeable bad connections, or found the circuit breaker for the headlights. My guess is it has to be a headlight switch or circuit breaker or faulty connection somewhere, just picking brains to see if anybody has any solution to the problem before I have to take and 8 to 10 hour round trip in the dark to Fort Riley on Thursday, half of it in the hours of darkness and potential snow. Thanks in advance for any help.

 

[gimpyrobb]

The 3 lever switches have a breaker in them. If you can't find any shorted wires, it might be the 3 lever switch going bad.

 

[Jon Giovani]

So the headlight circuit breaker is actually in the three switch light switch itself? That would explain why I could not find it in the wiring harness...

 

[gimpyrobb]

Yes

Some have installed relays so as to not stress the C.B. in the 3 lever switch.

 

[Jon Giovani]

Ok, so a couple more questions.
Are they like a standard 2 blade breaker, similar to the mtv or lmtv, or automotive breaker? And does it seem to be issues with the breakers, or the switch itself, for the most part?

 

[gimpyrobb]

The C.B. is internal. I've taken one or two apart and realized, its better(for me) to just swap out the 3 lever switch. Some you can open without destroying, some you can't.

I can't offer a good answer for your last question, sorry.

 

[Gunzy]

I would get a known good used one and retest the lighting, if it works fine leave in the replacement and all is good. That is how I repaired the lights on an M998.

 

[oboyjohn]

I have had the same problem up here in Canada with a 3 arm light switch installed in a 5/4 ton Chevy. The switch would warm up and the breaker would trip, usually at the worst possible time,when cresting a hill or going around a curve. As Gunzy said swap out for a known good one.