3 brush generator internal wiring

[wlmccabe]

I have six 3 brush generators, 2 Farmall Cub, 2 John Deere, and 2 spare. I have growler tested armatures and housings on all of them. All check good. After disassembling for cleaning and testing, I have internally wired them per the wiring diagram I found in two places online, which shows the insulated brush at 180 degrees to the ground brush as the third brush to terminal "F". The adjustable brush and ground brush are shown as the main brushes with the adjustable brush to terminal "A". I found a post for Oct. 2009 on this site, if my understanding is correct, that seems to reverse the brush and wiring order. I am not questioning anyone's knowledge or expertise, but I really need confirmation on which is right for the right internal wiring. My generators motor only when I ground the housing and "F" terminal. I am learning about 3 brush generators. Thanks to anyone who can help me get my generators wired right.

[Bill V in Md]

Check out the post in the following link:http://farmallcub.com/phpBB2/viewtopic.php?f=1&t=106932
You can also go to the Quick Links (top left of this page), then go to the PDF Manuals, then go to the Service Manuals / Delco Remy, then go to either the Delco Service Manual or Third Brush Generators.

Welcome to the Forum.

[John *.?-!.* cub owner]

IH uses a type A charging system, where the generator provides voltage and you control the charge by varying the ground on the F lead. I am not sure, but I believe John Deere uses a B charging system, where the voltage to the field is supplied externally, so the internal wiring of generators for the 2 are different.

[Bill V in Md]

I forgot to mention that you need two posts on this forum to have access to the on-line manuals.

[JohnMihevic]

The attachment below is a simple schematic of the 6V 3rd Brush Generator used on the Farmall Cub.

John M.

[Jim Becker]

. . . I am not sure, but I believe John Deere uses a B charging system . . .

I believe that Deere (at least the older ones) used an A circuit. I think they even used a lot of the same Delco components as IH. I think Ford used B circuits.

The attachment below is a simple schematic . . .

And unlike that other one that has been copied all over the internet, this one is correct!

[wlmccabe]

Changing the internal wiring to match the picture given on this site. Having a problem with one generator that motors only when I ground the housing and "F" terminal. Generator tested good on growler. Would this indicate insufficient ground on the ground brush or something else. I appreciate everyone's help with my "OJT" on my tractors.

[JohnMihevic]

Check your wiring so that it is like the wiring diagram. Use an ohmmeter to do basic troubleshooting.
If your generator motors when you ground the housing and the "F" terminal, the generator can't be wired as above. The field would have zero volts applied and in no way would be able to "motor".

John M.