Wiring a 1925 TT without an ignition switch

[Herr_Wiebold]

Howdy all,

So, I've been approaching the point of test running my TT rebuild, but haven't yet had a chance to rebuild my ignition switch unit... Does anyone know of a way to wire things up to test run with a bypass instead of the insulated switch unit? I can figure a reasonable way to do things myself, the biggest question mark I have is related to the Battery terminal on the coil box... for the car to run, does anyone know what needs to come in here (volts, current, standard DC from a battery, etc)?

Thanks in advance!
- Brett

[Henry K. Lee]

Well if it is an electric engine with a generator, not a wise idea unless you want to buy a new generator. Best to be patience and have everything ready to go at one time.

Just Sayin'

Hank

[TonyB]

First you want to make sure that when the engine does run, nothing is damaged.
So first disconnect the wire From the generator. Insulate the bare end of the wire then connect the terminal on the generator to ground. This will protect the generator from any damage.
Now connect a wire from the battery positive to the common bar under the coils in the coil box. You may want to put a switch in this wire.
A little hokey but it will do the job

[John kuehn]

I think I would go ahead and get the switch and wiring hooked up. Of course that’s my opinion but you will eventually need a switch.
The T ignition switch is pretty straight forward and not hard to clean up and rebuild if necessary. If the key still works the switch pretty well there are several earlier post about cleaning and repairing one.
Again it’s just my personal opinion but getting your ignition wiring in shape by installing new wiring and getting your switch in shape would be the way to go. You’ll be glad in the long run you did,
Good luck!

[HPetrino]

It's been a number of years, but when I finally got the engine back in my TT, the radiator installed, fuel hooked up, and wiring put back together I started cranking (no starter). I cranked, cranked and cranked some more. I couldn't get it to even pop. The only "shortcut" I used was a large 6V flashlight battery instead of a regular car battery.

So, after getting my breath back I started to run some diagnostics. It turned out that there was a short in the coil box. I took it apart, rebuilt it, put it back and tried again. Second or third pull and she was running.

The moral of the story is that I agree strongly with John K. Spend what little time it takes and put the wiring back as it should be. It there's anything wrong you want to be looking at the actual system, not some jury-rigged set-up so you can actually make progress and get it running reliably.

[BE_ZERO_BE]

Here are some color wiring diagrams on the MTFCI web site.

https://nebula.wsimg.com/3a0733937917a1 ... oworigin=1

Hope this helps.