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headlight grounding question

38Buick 80C

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On my '39 (and I have the '38 manual) it appears that most of the lights relied on metal to metal contact, when new. Such as.....the bulb housing was in contact with the socket, which was crimped into the reflector and the reflector was bolted or in metal to metal contact with the outer headlight housing which was bolted to the fender.

That relies on 4-5 different places to have good metal to metal contact. To resolve the problem, I have started soldering a ground wire to the bulb socket. File a clean site on the socket and attach the ground wire. On the other end I crimp and solder a terminal that has a large hole that the headlight to fender bolt will pass through. If you cannot find a terminal large enough, solder the wire directly to a washer.

This method removes several possible trouble spots along the ground circuit.

I have also tried tinning the bulb sockets, but if you can find a new replacement socket, that is much easier to replace the socket than try and get an old rusty socket to take solder.

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If the issue with your headlights is that they run too dim, it may not be a grounding problem. The current flow to the lights goes through the headlight switch, then the dimmer switch, and then to the light units.

The headlight switches on this era of GM-mobiles are NOTORIOUS for voltage drop, and no amount of cleaned-up grounding will solve the issue. When I converted the Roadmonster to sealed beams my solution was to use a bank of 6V relays and new feeder wires to the lights. I chose to use a separate relay for each of high beam, low beam, and driving lights. Finding 6V relays was the trickiest part of the job, but they are readily available through wwgrainger.com. Note: you'll also need the matching mounting base for each relay.

Alternatively, you can use ONE relay triggered by the headlight switch to power the dimmer switch. However, you still run the risk of voltage drop through the dimmer switch. Either way, the relays can be installed out of sight if you wish. If your car is one that is judged, you can argue that the alteration is a safety factor and should be exempt from points-deduction.

This really is easier to do than it is to describe. But oh, MAN, does it make a difference!


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OK I thought there was a wire soldered to the reflector housing (not the reflector but the piece it sits in). Where does the non-soldered end go???

Tom, You might say my headlights are so dim they are non existent....cause they are. I haven't got that far as I am running wiring right now, but I appreciate the heads up and I'll keep that in mind.

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