MTFCA Forum

One car I'm working on is a 1919 Magneto only, no starter, car. It is missing its magneto horn and bracket and horn/light switch and resistor and wires. It does not appear to have had a terminal block, and the key is on the front of the coil box. I need to reassemble all this.

What colors are each of the four wires going to the horn/light button/switch? Does anyone sell a harness for this or do I piece it together from wire-by-the foot?

Also is there a source, or a way to recreate the dim/bright resistor thing?

Thank you.

Mike, I have just removed a 'resistor thing' form the old car I am presently working on returning to the road. It is a simple winding of some copper wire about a ceramic looking core like coilbox insulators. It stands of the wooden firewall on two pieces of metal strap, one on each end. I have a second one I could send you for the cost of postage, but being of Canadian source, it may be a bit different to US examples.

Allan from down under.

The "Resistor" that is used on the non-starter Model T is actually an Inductor.
It is a coil wound around a laminated core.
The inductor acts like a variable resistor that varies with engine RPM (Magneto Frequency).
As your key is on the coil box, the inductor would have been mounted on the firewall.


 

 

Here is the wiring for the dimmer. The wires are to be insulated. Starting from the colored circle end they are tucked under the coiled wires
Horn wire should be 14ga

Thanks, that's what I was looking for.

Confirming I understand correctly:

The wiring itself is simply black cloth-covered with no fancy colors or stripes? With ring terminals and shrink tube?
(Did they have shrink tube back then, or is the original crimp insulation a piece of rubber tube?)

The horn wire is 14 gauge,
Are the light wires also 14 gauge?

On the color diagram, what is the "firewall junction" on cars without the terminal strip? I guess it's so one can swap the inductor without cutting wires. What does this firewall junction look like?

The hard wires from the inductor go straight to the horn/light switch with no junctions.

I'm hoping to be as "correct" as I can get it. Because why not?

Thank you.

Here is the best photo that I have.
 

PuzzleTFord wrote: ↑

Tue Feb 13, 2024 3:30 pm

Thanks, that's what I was looking for.

Confirming I understand correctly:

The wiring itself is simply black cloth-covered with no fancy colors or stripes? With ring terminals and shrink tube?
(Did they have shrink tube back then, or is the original crimp insulation a piece of rubber tube?)

The horn wire is 14 gauge,
Are the light wires also 14 gauge?

On the color diagram, what is the "firewall junction" on cars without the terminal strip? I guess it's so one can swap the inductor without cutting wires. What does this firewall junction look like?

The hard wires from the inductor go straight to the horn/light switch with no junctions.

I'm hoping to be as "correct" as I can get it. Because why not?

Thank you.

I would make the wires from the magneto to terminal block to switch to horn to ground 14ga. Wires to lights 16ga as indicated in the diagram. Lang's sells Horn wire , black. To insulate, shrink tube, then a bit of black silicon seal to make t look authentic.

There are three horn switch styles. One is just a button on top of the steering column. The other two are similar in that they clamp onto the steering column. One is just a button and the other is a button that rotates to turn he lights on. The color diagram is for the combo switch

Yes, I have most of a combo switch and two brackets (one black one chrome?). And I'll get both sizes of wire.

Re: the picture
Ah-ha!
There's a hole in the firewall, for the magneto wire to go in and the two light wires to come out.
And the "junction" looks like it's just a small right-angle tab that I think I remember seeing in one of the other drawings I'll try to find. It's location starts to explain why the 5-wire commutator harness with the 5th wire for the headlight has such a short headlight wire, because it only goes to the junction on this end.

One of my challenges is the car I'm helping with is in another state, so between visits I have to go by memory, or squinting at photos I took before I knew what I should be looking for.

Thank you.