Headlight ground

[ModelAArmy]

Pardon me for not knowing what I am doing but I dove into model A restoration. I bought a model A from an estate in which most of the restoration was done and only some things needed to be done. I am now trying to get the headlights to work.
The car has been converted to 12volt negative ground. The headlights have a 3 prong connector with all 3 wires feeding the socket being hot so my problem is the ground.

I ran a jumper from a good ground to a screw in the socket and the lights worked fine on high and low. The cowl lights are not currently hooked up. So my problem is the ground. Can anyone suggest how to ground these lights. Thanks

Tom

[bruceincam]

Each of my headlights has a ground wire running through the stainless conduit to one of the radiator shell mounting screws as a ground. The other two wire in my conduit are hot --- one for high beam and one for low beam. Three wires in each of my stainless conduits. I'm not sure why all three of your wires are hot ---- you have low beam and high beam --- two hot wires ought to do it. Somebody else will have to tell us why all three are hot. Seems like one of those should be the ground.

P.S. I'm running 12V negative earth with Halogen bulbs if that makes any difference to you.

[nkaminar]

Hi beam, low beam, and parking light. Three hot wires.

The recommendation has been to replace one of the rivets with a screw and run a ground wire from there to the socket. You have to drill out the rivet and do some tapping. I think you will find the details in The Model A Mechanics Handbook, Volume II. (The green one.) See https://www.snydersantiqueauto.com/p...0033&cat=41621

[ModelAArmy]

Thanks for this info. I have that book and will look for solution.

[TomInCologne]

I soldered a wire onto the adjustment spring behind the bulb because i didn't want to drill into the rivets...

[Patrick L.]

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Yep, just run a wire back thru the conduit to a good ground. Kinda common.

[ModelAArmy]

I am sorry but I need for more help. I have seen on a page from a vendor where they they put a screw in the hole in the rear of the lamp canister and ran a wire inside the canister. I have the hole in the rear of my canister. The other advice about running a wire to ground from the light socket. Where would I attach the wire in the canister.

[ModelAArmy]

Well I made some progress. I wired a jumper from the socket to a screw at the rear of the light canister and it solved my ground problem however another issue arose. There is a fuse installed on the headlight wire separate from the fuse on the starter. The cowl lights are not hooked up and there are 2 wires dangling from the frame mid Coach. I assume these go to cowl lights. There are dangling and not touching each other or the frame.

Now the problem. When I switch the light switch to the parking light position, it blows the headlight fuse and I lose power to the headlights. When I replace fuse, headlights work again but fuse is blown when headlight switch is turned to the parking light position.

Is the switch bad or where do I start to troubleshoot this issue. Thanks

[ModelAArmy]

Sorry,

I have done more research and the two leads mid Coach are the brake light wires. I do not have a cowl light disconnect and to install one, it says to disconnect the parking lights. Since I have 3 hot wires going to the headlights, how do I disconnect parking lights. How do I tell if I have parking light in my headlight. Thanks for any help.

[1930artdeco]

Sounds like they wired the headlights for parking light at the top of the reflector instead of the cowl lights. It is possible the previous owner got the wrong wiring harness and it shorts out when you turn it on. You should only have two wires plus a ground wire in the head lights if you have cowl lights. The cowl lights are wired up differently-sorry I cannot remember how they are wired up at the moment.

Mike

[1930artdeco]

Ok, you beat me typing. Parking lights are at the top of the reflector in the head light. It may be shorting out, hence the fuse blowing. As for disconnecting them, there should be a bullet that you can pull out which will cut power to them.

Mike

[ModelAArmy]

Talked to fellow club member and got this advice. I have sealed beam lights with a 3 prong socket. He stated that one prong is high, one is low and the other is ground. Is this correct.

30 coupe is my car

[ModelAArmy]

Thanks for everyone’s help because I solved the issue. Previous owner installed sealed beam sockets and sealed beams. He used the 3 wire harness to go to each light. These wires were for high, low and parking lights. He hooked the high and low wires to correct socket location but instead of grounding the 3rd wire of the socket, he wired it to the parking light wire. This explains why high and low lights worked when I installed an alternate ground. I do not have parking lights in the headlights and so when I sent power to the ground socket via the parking light wire, the fuse blew.

My question now is, after I properly ground the sealed beam socket, can I leave the parking light wires disconnected and taped up. Thanks

[Badpuppy]

Yes you can. The parking light wires run forward to the headlights. When cowl lights are used instead, the park wire runs from the lighting switch out of the harness to the side to join the cowl light harness. You could cut the wires out of the harness and rerun them to the cowl lights if you wish, then repair the looms with friction tape.

[ModelAArmy]

Thanks for the info on disconnecting the parking lights. I will need to install turn signals and was planning to use the cowl lights for this purpose. Would it be better to hook the cowl lights as parking lights and turn signals or just turn signals and leave parking lights disconnected. Thanks it is getting to be fun figuring this out and the advice I get from more experienced owners is appreciated.

Tom in Texas

[Badpuppy]

Parking and turn need to be separated because of the different intensity. Vendors sell kits to combine the two by changing the cowl socket and reflector, but I think you'd be better off with separate housings, or don't park in the dark.

[TomInCologne]

on a side note...
i want my parking lights to illuminate whenever i have my headlights on. A straight connection from the headlight bulb to the parking bulb won't work as headlights would be on whenever i turn on my parking lights. The advantage is that if one of my headlight bulbs burns out i still have some light on both sides and other drivers don't think i am a motorcycle...



I am thinking about putting some diodes into a connection between the headlight bulbs and the parking bulb. Am i thinking wrong? I have bought some 45V 15A diodes...

[katy]

Originally Posted by TomInCologne

I am thinking about putting some diodes into a connection between the headlight bulbs and the parking bulb. Am i thinking wrong? I have bought some 45V 15A diodes...

That should work, 2 diodes in parallel, 1 from high beam and one from low beam, for each parking bulb. Watch polarity of the diodes, if you're unsure try it w/one diode first.