Headlamp low beams out...?

[binx]

Hi:

My main headlamps spontaneously died the other evening as I was driving up the canyon. The high beams are fine, but the low beams won't come on. I thought I smelled a little burning smell when the lights went out...

I happened to have an extra dimmer/signal switch stalk, so I tried replacing that, but no change. And I've poked around behind the dash and in the center dash (military 6-position switch) looking for a little charring or something that might signal where the magic smoke was let out, but no luck. I wonder what all of those relays in the center dash area do.

Fuses look fine. Suggestions on how to debug further please?

Thanks,
Eric

1980 Series III 109" military, "Gertrude"

[luckyjoe]

Check inside the rad panel, behind the grill - should be a rubber bullet connection block feeding both headlights. Next trace these wires...

[Ncrover725]

I am by far no wiring expert. I did have the same problem though on my 109. When I have no lights at all I re tighten and check all the connections behind the 6 way switch. I ensure I have good contact on all the wiring leads. This has always fixed the problem. When I only have high beams I have found that it was due to my dimmer switch one time and the second time I had a worn wire where it passes through the bulkhead from the dimmer switch.

[scatterling]

Check inside the rad panel, behind the grill - should be a rubber bullet connection block feeding both headlights. Next trace these wires...

The red/blue wires should be for the 'dip' beam (regular) and the white/blue wires run the highbeams. Check all the bullet connections carefully.

[Skookumchuck]

I had this issue as well it turned out to be a defective dimmer switch. I always had high beams but the low beams worked intermitantly. When I changed the dimmer switch both worked fine.

[binx]

Thanks everyone. I spent some time plugging and unplugging some of the bullet connectors around the radiator panel and behind the dash. At some point, I must have (perhaps inadvertently) done something that turned my lights back on. I'm not really sure what.

Regardless, a lot of those little bullet connectors are corroded or otherwise janky. And I have a bunch of other weird connectors too -- crimp connectors and funny bullet connectors with arrowhead rubber casings. When it's above freezing here at some point, maybe I'll embark on a little DeOxIt project and replace some of the nasty connectors...

Thanks again, Eric

[jac04]

... funny bullet connectors with arrowhead rubber casings.
Those are the military type connectors that are supposed to be more weather resistant. Try to keep them. Clean up all the connectors, then use a little dielectric grease on them to keep them from corroding in the future.

[binx]

This might be a dumb question, but dielectric grease is non-conductive. Wouldn't I want to use a conductive grease if I'm lubing the bullet connectors before reassembling them?

[SafeAirOne]

This might be a dumb question, but dielectric grease is non-conductive. Wouldn't I want to use a conductive grease if I'm lubing the bullet connectors before reassembling them?


No.

[binx]

If anyone else is curious, Wikipedia has a decent explanation:
http://en.wikipedia.org/wiki/Silicone_grease#Dielectric_grease

It seems like the dielectric grease shouldn't be applied to the actual bullets when reassembling, but only to the rubber bits, sort of as a protective layer.

[bkreutz]

Grease (dielectric or otherwise) doesn't improve the electrical contact it just keeps out oxygen that is needed for corrosion to start, so rather than improve the continuity it actually preserves it. I use dielectric because it won't allow the voltage to travel through the grease (to some unintended place:)) the metal to metal contact of the connectors is where the transfer of electrons occur.