VCCA Home Forums TECHNICAL - GENERAL Electrical - 6 volt How do you get a secure ground for the lights on 1929 AC.

How do you get a secure ground for the lights on 1929 AC.

Frank Cerutti
Queensland
Australia
1929 AC Tourer

Clean metal joints & screws, and tight connections should do the trick.

I did this a few years ago when restoring my 1929.

for the headlamps you need to ensure that you have clean metal to metal contact between all mating parts, that means NO paint, no primer. both of these will cause issues. same with brake/tail lamp. also i put in an extra ground wire from light socket to light socket (mainly from the light sockets to the socket that goes in the housing where the power comes in from light switch/dimmer). this all takes time and effort, but in the end you end up with good ground and lights !! only other option is to run a dedicate ground wire from chassis/frame to the light socket on each side of the car.

details are here: https://vccachat.org/ubbthreads.php/topics/404323/1.html

Thanks BearsFan315. Your summary posting is excellent. I had concluded that the W springs securing the bulb holders grounded these components effectively. However, I’m not convinced that bare metal, which will rust and put up a high resistance barrier is the best answer upstream of the reflectors.
There is a hint about connecting a wire between the reflector and the chassis, but there is no obvious way to do that given all the connections are plug and socket. Maybe another wire secured by the bucket gimbal nut and threaded through the staunchion? Not very reliable since we are considering connection to the reflector.
Frank Cerutti
Queensland
Australia
1929 AC Tourer.

everywhere i stripped to bare metal i used carbon conductive grease to help prevent corrosion, stuff is black so hard to tell it is there on the black components, plus it will not disolve or wash away in water, and it is highly conduction, also used it on my ground wires to the frame.

just dont get it on you, or you will be carbon black for a few days

Sounds like the voice of experience to me.

Hi BearsFan315. I must admit I am not enamoured of the carbon conductive grease answer.
As your posts on this subject show, a good ground can be achieved internally to the headlight housing by socket-spring-reflector-clamp ring-housing. So all that has to be navigated is housing-headlight bar-fender bracket-frame. And as you said in post #423317, there are all screwed connections. I'm considering using sections of braided copper ground strap as a washers instead of grease.

Frank Cerutti
Queensland
Australia
1929 AC Tourer.

Wouldn't just plain di-electric grease work?

The ground connection needs to be mechanical (clean components touching each other and thus, providing a good path to ground).

It is unfortunate that dielectric grease has the word 'electric' in its name. It is actually an insulator, not a conductor.

After a good mechanical ground connection is made, dielectric grease can be smeared on top of the connectors and help keep the outdoor elements out so the ground connection remains corrosion free.

Here's an explanation: https://www.motortrend.com/how-to/what-is-dielectric-grease/

Cheers, Dean

Di-Electric grease is NON Conductive, it is used to keep water(liquids) out of a connector connections and keep them from corroding :)