I'm working on a Model T salad, a WWI Light Patrol Vehicle on a 1915 frame with a 26/27 engine and engine mounted coil box. I will NOT be running headlights or tail lights.
4 wires from timer to coil box. Apark plug wires. Wire from key ignition switch to bottom of coil box. Starter.
Looking at wiring harnesses, they have 4 wire or 7 wire or various combinations, or go by year and I'm a little of both.
Which wiring harness would work for my application.?
I'll hang up and listen. Also I'm presuming I can use a 26/27 wiring diagram? Just take the headlights and trail light and brake light out of the loop?
Hmmmmm. Silly queston, I guess.
IT kind of depends on what dash you are using too. Are you using a '26 - 27 ignition switch?
If it were me, I would try to make everything from the same year. A 1915 vehicle would have a firewall mounted coil box, which would work with the 1915 harness.
A 1926 - 27 non generator vehicle would use a different harness to match the engine mounted coil box and the dash mounted switch panel.
Royce, understand, but I'm using what I got from the family tree. And, that is a 26/27 engine on a 1915 frame. And, as this would be a WWI vehicle, I'm building it under the premise of a motor pool post war rebuild with a 26/27 engine.
I'm confused now as my 26/27 engine has both a starter and a generator.
My intention will be to use the wood firewall but not the coils. I'll use the coil box mounted on the engine. But will use a firewall interior mounted coil box as a first aid box.
May just have to wire this up as I go along.
Are you going to use the generator and a battery?
I'd use the 26/27 engine harness since you're using the 26/27 coil box. It's shorter and is routed over the front of the engine to the timer. It uses different clips too. Use the 26/27 clip arrangement.
To use the generator, you'll have to run that wire yourself unless you buy the headlight harness. Personally, I'd use the headlight harness even if you aren't going to run lights NOW. It would make it easier if you ever did add lights to make it street legal. And the harness will come with the generator wire.
I think that you answered your own question. The 'comm loom' for a motor mounted coil box is unique and routes differently than previous years...it only contains 4 wires and is not the 4 wire lamp inclusive set!
You need a 'hot' to feed the coil-box and by choice are not using headlamps...so what is the switch? A normal 26/27? Either way, just run from the switched outlet to the stud on the coil box...
So you have no need per se for a driver side loom...
Ah, but now we have a generator...easy enough to run a single yellow wire in a cloth loom along the original path...and since there will probably not be a terminal strip... it has to go somewhere. Again, if you are using a std 26/27 switch-plate with an ammeter, just wire it into the ammeter.
Inside the car use the std battery to switch arrangement and ammeter to battery arrangement...instead of stopping at a terminal strip, just wire through...my only additional thought is those in the know always want 'some' resistance in the line going from the cut-out to the battery (i.e. must flow through ammeter)and apparently more than the voltage loss caused by the wire itself. Hope they chime in with what to do about that...maybe it is as simple as equal resistance or inductance...then again, since you are talking a convert in theory, any switch, 19-27 would work...
One of those 7 wires you noted (the larger one) was for the generator cutout to fire wall terminal panel connection.
Another one was for the dash light switch to bring electricity down to the right head light.
There was another wire from the right light head to the left head light and another wire from the left head light to ground.
Both head lights were single element bulbs, powered by the magneto.
If you use the 1926 generator, with 6 volt dc lights, you need the 7 wire set.
If you use the 1926 coil box on the engine, you need a different four wire set for the coil box and another different 1926 set from the ignition switch to the firewall terminal block and another 1926 set from the firewall terminal block to the headlights and tail light.
NOW WE'RE GETTING SOMEWHERE!!
Thanks guys. I'm used to another vehicle restoration that I did that really had one main wiring harness and maybe a few seperate wires for an accessory.
This sounds like one harness for the timer and coilbox and then a bunch of sub assemblies or seperate wires for the remainder.
The only switch I am planning on would be the ignition battery switch to energize the coils. I will be using the generator since I have no idea the condition of the mags until I get much further along in the restocreation.
Thanks for the starting point.