I have a 76 Eldorado with 62k and am having a problem I cant seem to fix. I replaced all the headlights with new old stock Wagner's. The left low beam (outside) headlight has went out twice now, they all come on fine, then the low beam goes out and then shortly after that the high beam filament of that same headlight goes. I checked the replacement before I put the second one in, I got 1 ohm and 40 ohm's with the meter.

Ive checked the voltage at the plug and it's 11.3 volts for the low beam, 10.3 volts for the high beam of that headlight. When the high-beam foot switch is activated, I get .2 volts across the low beam filament at the plug (if that makes sense).

The foot switch and the twilight sentinel "seem" to be working as they should. In 2003 there was an engine fire and insulation was charred and some wire sections were replaced, but the only part of these wires that were affected was at the firewall where some of the plastic connector for the harness there was melted (a little). This is the first time Ive experienced this though, and the reason I replaced all of them was that this headlight was out.

I think there must be an break somewhere where its getting too many amps or too much voltage~ The new old stock headlamps are very vintage, but the light was out before I started the replacement. The fuse doesn't blow at the panel.

I have the shop manual, and the electricity comes from the dimmer switch to that headlight then on to the RH low beam (and the LH/RH High-Beam); which confuses me because all the others work fine.

Does anyone have any thoughts about this? I would love some help!

 

I would look at the connector and the ground wire for the affected socket. Since on side works and the other is having a problem.