'52 8N Need Electrical Help

NCFixer

New User
Howdy, I found this site searching for some answers. I am helping a non-mechanically inclined uncle with a tractor problem. As he tells me, it's a 1952 8N, owned for 30+ years, and lately basically over a couple days' usage the battery dies.
He has replaced the battery (still 6V positive ground)
new voltage regulator
generator rebuilt by local shop
wiring harness replaced last year
fan belt tight, not slipping
I have an older Fluke test meter, and show 6.1 volts at the battery, when running, also 6.09V at the voltage regulator.
I have shorted the 2 terminals on the VR to ensure it is polarized.
The only other clue is that the ammeter is no longer registering. it's the old style where the wire passes through the metal loop on the back. He said it used to work, but now doesn't.

My question is what terminals do I test voltage or amperage at to verify if it's charging? With everything new, I don't know what to check next. The new wiring harness seems to be installed correctly as best I can tell, but I'm wondering if a wire got crossed with that. I'm sure I'm missing something obvious but I don't know what to look at.
All help appreciated, thanks a lot.
 
Voltage readings indicate no charge. Verify ground and field wires between VR and generator. Temporarily tie the two generator barrel terminals together and measure battery voltage with engine at speed. If no increase, with engine running, add another temporary jumper between generator Arm terminal (on rear of gen) and the ungrounded battery terminal. Again measure battery voltage. Remove this jumper before stopping engine.
 
(quoted from post at 08:04:25 08/03/18) Voltage readings indicate no charge. Verify ground and field wires between VR and generator. Temporarily tie the two generator barrel terminals together and measure battery voltage with engine at speed. If no increase, with engine running, add another temporary jumper between generator Arm terminal (on rear of gen) and the ungrounded battery terminal. Again measure battery voltage. Remove this jumper before stopping engine.
Thanks for the reply. Any chance someone could post a diagram with those labeled? I think there are 3 terminals on the generator, so I want to make sure I'm looking at the right ones.
Also as far as verifying the wires between VR and generator, I did check for continuity (and it does beep) if that's what you mean.
Thanks,
 
"Also as far as verifying the wires between VR and generator, I did check for continuity (and it does beep) if that's what you mean. " That isn't good enough unless you have both wires disconnected at both ends. 8N10001
4Alm2Cl.jpg
 
OK thanks. So just because I won't have a computer handy, want to make sure I'm straight before I'm out in the barn next time.
rUEPs19.jpg

So disconnect the wire from F to F , and A to A between generator and VR. Verify continuity on each.
Then reconnect, and jumper between F & G on the generator, check voltage between + and - battery terminals. Looking for something a lot higher than 6 I guess?
Likewise next jumper A on gen to - battery terminal, again looking for a higher voltage?
Sorry for repeat questions, just want to make double sure before getting out there and starting in. Thanks a lot.
 
(quoted from post at 15:51:30 08/03/18) OK thanks. So just because I won't have a computer handy, want to make sure I'm straight before I'm out in the barn next time.
rUEPs19.jpg

So disconnect the wire from F to F , and A to A between generator and VR. Verify continuity on each.
Then reconnect, and jumper between F & G on the generator, check voltage between + and - battery terminals. Looking for something a lot higher than 6 I guess?
Likewise next jumper A on gen to - battery terminal, again looking for a higher voltage?
Sorry for repeat questions, just want to make double sure before getting out there and starting in. Thanks a lot.
es, that all sounds correct. Looking for about one volt increase when & if charging. Be careful to find A, F, B markings on the VR terminals. I say this because in your drawing, the terminals are L to R, are A-F-B, whereas on your tractor they will be B-A-F, I do believe.
 

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