Allis Chalmers C wiring disaster

[Super_C]

Hi all, I am working on an Allis Chalmers C and the people that left it for dead didn't label anything on the wiring harness. There are 4 wires coming out by where the engine and bell housing meet together and there is already a two worse running to the starter and there is another one that the online pictures told me to put there but there is only one extra one supposed to be there. there is a 12 volt conversion done still using the generator not an alternator. any help is appreciated and I am at my wits end with this thing.

 

[560Dennis]

Could you post some photos of the what your concerns are ?
I’m sure comments will fix you right up .

 

[Super_C]

well I can try to get some pics of it the advisors are very strict about who goes in the shop and when.

 

[Jim.ME]

I take it this tractor is in your school's shop so you have limited access to it.

How did you confirm the generator is 12 volts? Is the tag still on it?

A 12-volt generator needs the correct regulator and would not need to use all the terminals/functions of the multiple position light and charging switch in the box below the steering wheel, the 6-volt generator used.

Below is a link to an Allis Chalmers manual for the G, B, C, and CA. There is a wiring diagram in the C section of the original 6-volt wiring. You might find a wiring diagram for 12-volts but details on the generator and regulator will be needed, as well as the gauges and switches it has. Your description won't do it. Try drawing a sketch of what you have. Pictures can help but a bunch of wires in a loom or taped together don't tell much

Allis Chalmers "Knowledge Means Power" Manual for G, B, C, & CA

 

[Super_C]

There is a resistor on the generator and on 6 volt tractors I've seen don't have them and I was told by the previous restorer teacher that they had conveted the tractor to 12 volts.

 

[Jim.ME]

There is a resistor on the generator and on 6 volt tractors I've seen don't have them and I was told by the previous restorer teacher that they had conveted the tractor to 12 volts.

Resistors in 6-to-12-volt conversions are generally used ahead of the original 6-volt coils to save buying a true 12-volt coil. I can't say I have seen a resistor mounted on a 12-volt generator as part of a conversion. If you look at the original 6-volt wiring diagram the resistor was controlled by the charging/light switch. In the low position the field current went through the resistor to reduce the charge rate. When in lights on or High position the resistor was bypassed, and the field receive full current to give a higher charge rate.

Sounds like a good sketch of what is there is the first step, along with seeing if you can identify the generator and regulator. Figure out what you have to start with.

 

[560Dennis]

Since its in a shop , they should be able to initiate corrective action .
Question did they do the work ?

 

[Jim.ME]

Since its in a shop , they should be able to initiate corrective action .
Question did they do the work ?

See his replies in posts #3 and #5. The poster is about 15 and the tractor is in a school shop, his initial post indicates he is the one assigned to work on it.

 

[Super_C]

This is my first year in high school and tractor restoration and also the first year of us working n that tractor there as a group of people we think around 8-10 years ago that tore the thing down but we don't know because half the parts were missing and we've had to order a lot of new parts

 

[Bryce Burden]

Without being there to see it in person, I can't tell what wire goes to what. These old tractors don't take much wiring to run, but I have discovered that after 60+ years of previous owner fixes, the wiring on them can be a true nightmare. We bought a pair of Allis WDs a few months ago, both ran but the wiring was a total rat nest, I spent a few hours on both of them trying to figure out what went to what and why this wire was cut and this wire added. I finally gave up and ripped out the whole thing and started over. Took me a couple hours to build a wiring harness, but it was much easier than trying to sort out the mess that was there before. If you have a manual for the tractor it should have a wiring diagram in it, with that you should be able to build a new harness pretty easily.

There are only about three circuits these old tractors need, ignition, charging, and lights. The most difficult circuit to wire is the charging system IF you are still running a generator, and even then they aren't bad.

 

[Super_C]

I found a diagram that I think gave me the info on what I needed

 

[Jim.ME]

I found a diagram that I think gave me the info on what I needed

Share the diagram with us. You asked for help, keep us in the loop, we may have things for you to check as you go along to help prevent back tracking later.

 

[Super_C]

https://drive.google.com/file/d/1nvxDDuq8gSc9ex2Y4n4wH3OWvMt8Foeb/view
that is the manual with the wiring diagram I see the tractor on Wednesday and will update you all when I can

 

[Jim.ME]

https://drive.google.com/file/d/1nvxDDuq8gSc9ex2Y4n4wH3OWvMt8Foeb/view
that is the manual with the wiring diagram I see the tractor on Wednesday and will update you all when I can

Ok that is the diagram in the manual I linked for you. The diagram in the manual for the tractor is as it was built, a 6-volt system. You said the tractor has been converted to 12 volts so remember that diagram will need to be modified unless you are going to restore it to 6-volts.

 

[Super_C]

I I'll probably just use the 6 volt diagram and see what will need to be changed

 

[Dick L]

Hi all, I am working on an Allis Chalmers C and the people that left it for dead didn't label anything on the wiring harness. There are 4 wires coming out by where the engine and bell housing meet together and there is already a two worse running to the starter and there is another one that the online pictures told me to put there but there is only one extra one supposed to be there. there is a 12 volt conversion done still using the generator not an alternator. any help is appreciated and I am at my wits end with this thing.

Would this help?
https://public.fotki.com/DickL/parts_drawings/wireing_diagram_3.html#media

 

[Super_C]

it might I'll have to look at the tractor again

 

[Jim.ME]

The wiring diagram is the same one that is in the linked manual.

When you see the tractor again you need to:

1. Determine if it has a 12-volt generator and regulator.

2. Decide if it is going to be 12-volt or go back to 6-volt.

3. See if it has a magneto or distributor.

 

[Super_C]

that's what I thought