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I just encountered a problem on my 79 that really has me stumped. Everything with the lights has been fine and I switched to high beam last night and both lights went out. Does anyone know what would make both of my headlights go out when I switch to high beam?
Check the relay. Also, you didn't mention if both high and low are out, or just high. Distant as it may seem, check the bulbs. I once had both lows go out at almost the same time. Ended up being the filaments just coordinated their demise. High beams aren't used as much and usually go into the trash in working condition with their low beam cousins.
CraigandJanet it is only the high beams, I had the low beams on and switched to high and both headlights went out.
Ok. I'll look at mine, and at the schematic for yours when I get home tonight, and see if we can work out a logical troubleshooting routine. Shouldn't be hard to find.
Looks like Big G got it right the first time by suspecting the dimmer switch. My wiring diagram doesn't show any relay. Power comes from the LIGHT SWITCH to the DIMMER on a Yellow wire, then splits at the DIMMER to a Tan wire (Low Beam) and a Light Green wire (Hi Beam and Hi Beam Indicator). Ground is common to both Hi and Low, so that's eliminated as a problem since Low Beam works. The only circuit breaker in the system is before the LIGHT SWITCH. The switch isn't fun, so before you do anything, unplug the headlights at the bulb and run a continuity check on each filament. Both the Hi Beams may be out. Stranger things have happened, and one of the Hi Beams may have already been out for a while and you didn't realize it. Let us know...
Last edited by CraigandJanet; Oct 19, 2005 at 06:22 PM.
My 77 did the same thing a while back. Turns out that the rod that switches the switch, was bent. Only switched the low beams off, didn't complete the transition to high. There is also room for play if the switch itself becomes loos where it is mounted. Straighten the rod and secure the switch!
Same thing happened to me. Was the dimmer switch. It was in the middle of the night on a unlit backroad. Hit the switch, the lights flickered then died. I just had to guess where the shoulder was. I fiddled and fiddled in the dark, because stupid me, i didn't have my flashlight in there. Got them to come on, but they would only stay on bright. Needless to say, I got a lot of lights flashed at me that night. You gotta do what you gotta do.
I just encountered a problem on my 79 that really has me stumped. Everything with the lights has been fine and I switched to high beam last night and both lights went out. Does anyone know what would make both of my headlights go out when I switch to high beam?
Could be the circuit breaker for the headlights is weak--or there is a real short in the high beam circuit.
Hey guys,
Thanks for all the information to troubleshoot this!! It turned out to be a loose connection at the right headlight, it took out both hi-beam lights. Couldn't have found it without your help, I really appreciate all of you!