1934 Ford Electrical Part

Joebeeker

Junior Member
Good Day/Evening Everyone:

I am currently replacing the wiring system of a 1934 5 window coupe and have a question about a part that was installed in the car.

If you look at the attached pictures the device on the right is the component in question. It was mounted on the inside of the car on the firewall and wired into the electrical system. It mounts at the correct position that the new wiring harness wires up to where there should be the fuse mounted to the firewall.

The components on the left are circuit beakers (20amp and 30amp) and were wired into the electrical system.

When I do an ohm check through the component on the right it gives me zero ohms. It looks like a some kind of relay/fuse which monitors the current flow through the wiring and opens when too much current is present I guess.

If anyone has any ideas what this component is please advise.

Thanks to all for looking and any help in advance.

Joebeeker
 

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Joebeeker ......................
That is your ignition resistor. That keeps your coil from melting. With out it, your coil will melt down.
I'm sure that someone will give a more technical answer.
MIKE :)
 
if you have any catalogs, it's the fuse block and coil resistor...40-12250-A in Mac's catalog....hope it's still a current number....Mike
 
I reckon that is out of a 40's Ford and is not correct for your 34. I think it is the headlight relay that those later models had. You are correct; the fuse should be there, and to the left of that should be the ignition resistor, looks like it has been removed and those blocks fitted instead. The 40-12250-A unit as in the above post is what you need for your 34. Brian
 
The resistor by itself (18-12250) is available if that is all you need. This is the resistor for the 6 volt stock coil.
 
Thank you everyone so far!

When the owner of this component switched out his 1948 Flathead for a 1936 Flathead for his 1934 5 window coupe he put the 1936 Flathead on a homemade test stand and wired this component into the coil circuit and when he started the engine he exploded his original 1936 style coil. I then took out this component and put a 2 ohm resistor in its place and the engine ran on his test stand. When I was replacing the wiring harness in the car I found the 2 ohm resistor for the ignition circuit.

I also looked in the catalogs and could not find a component like this one but there were like you'll stated that had a resistor to the left and a fuse to the left.

Thanks for all the information!

Joebeeker
 
It is an after market device. The risistor is not on it. It has two small circuit breakers And the main. G.M.
 
Add the ign resister and use the breaker instead of the fuse normally used in a 32-8. With the circut breaker (thing in the metal box with holes) if a short happens or something goes wrong, you will not totally loose your lights, it will start buzzing off and on giving you a chance to pull over and find the problem. With the fuse, when it pops, thats it and everything goes dead.
 
i stand corrected...after looking more closely at the pics in the catalog, it doesn't look like what i said it was....kinda looks like part of it is a lighting wire circuit breaker assembly?? 11A-12250 in Mac's catalog....Mike
 
Some more background that may shed some light on this.

About the '34 coupe, it was owned by a long time motorhead and drag racer. He also was a retired technician from a major office products company with more than his share of electronics experience/knowledge.

Problem was that he did not necessarily follow conventional approaches ... whatever that means. Neat logical wiring was not high on his list of priorities. Attempting to work behind him could be challenging.

But, that said, he was the go-to guy to solve a problem.

When the current owner (not Joebeeker who is helping him) bought the car, it had already been converted to 12V neg ground and used a coil adapter with a remote mounted modern coil.

You can bet your last dollar that the right amps were going to the coil ... again, problem is/was trying to figure out how this was accomplished (... did you know that the cigarette lighter will provide a certain amount of resistance?)

Anyhow, inside the perforated metal part of the item in question is a coil of heavy wire ... if I remember correctly. For proper resistance, perhaps it should be tested hot. If Joebeeker found another resistor up under the dash, or elsewhere, that would make perfect sense.

"and when he started the engine he exploded his original 1936 style coil."

"Original 1936 style", yes, but rebuilt by "Skip" as 12V neg ground ... and it was the second Skip-rebuild. The first merely burned. The second in fact blew the coil housing apart (I was on vacation in Montana and nowhere near the scene.)

A little further into this, AFTER the first coil burned up, Skip was asked what kind of resistor should be used with his rebuilt coil. His answer was, "I don't know." This supports some discussion that's already taken place on this board about figuring out your own requirements and in which Bubba has been very generous with his advice on how to calculate/do it.

I hope this additional information will help in the discussion.

My standard electronics avatar added below:

Hoopknife-1.jpg
 
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