The Stovebolt Site Forums The Shop Area General Truck Talk 37 1/2 ton manuel

Is there a better book for a 37 truck than the blue shop Manuel? I am looking for something that shows more detail? Would like to do my wiring harness as close to original as possible. Thanks for any help with this. Bill

Bill
Other than the Engineering Specifications publication I am not aware of anything. That is or was available online via the GM HeritageCenter. It does not have the level of detail needed for the wiring, however. The harness that cam with my ‘37 was an aftermarket and unlikely to have been even close to as the original. Rhode Island Wiring or YNZ might have the info you need and likely the correct materials as well.

The '37 has a voltage cutout instead of a voltage regulator. If you are going to retain the original voltage cutout, I believe you will need to use the original headlight switch which includes a setting that boosts the generator output so that headlights and options such as a heater or radio don't run the battery down.The switch includes a resistor for when there is no load other than the ignitions system, so that you don't overcharge the battery. This is my understanding of the original system which my '37 retains. I have been told this system is the same as old tractors. I kind of like it as you have to think about what your electric system is doing and watch the ammeter while driving. A little less automatic than when using a voltage regulator. I only have a heater in it so it is no big deal.

If you want a copy of the original wiring system I can send you a photo (too big to fit in my scanner) that came with my harness from Rhode Island Wiring.

Regards,
Kent

I guess I didn't explain exactly what I was looking for. I am converting to 12volt with alternator. I am looking for pics or drawings of how and where the wiring goes through the cab and along frame to engine, headlights, and back to tail lights. My harness was completely gone on the truck I'm doing. Not worried about original but would like to see where original went. Thanks, Bill

I think I can answer that for you. The wiring harness from the dash exits the cab, along with the speedometer cable, through a gap between the toeboard and bottom edge of the firewall just to the left of the steering column. The harness then connects with the dimmer switch just beneath the floorboard. In this area beneath the floorboard the harness connects with the hydraulic brake switch on the master cylinder and sends a wire to the gas sender in the underseat tank. The forward part of the harness goes forward along the frame to below the left headlight. Wires then go to the two headlights from there. The wires to the tail light just follow the same left frame rail back to the light.

There is no harness penetrating the firewall like in later trucks.

Kent

Kent, sent you a P.M. Bill