John Deere A generator........

Hi guys; restoring my "A" that I bought from an individual; noticed the amp guage NOT working; with test light and engine running there are 2 big wires "hot" on the regulator; the third small wire is NOT hot. Neither wire on the generator is hot either....pull it off and look inside? Thanks.

Yes, pull it off and look inside. Do this for 2 reasons, to visually look it over, clean it up, and to see what type generator it has on it.

I'm thinking it originally had a 3 brush generator and a cut out relay. But, it could have been upgraded to a 3 brush with a regulator, or a 2 brush with a regulator. There were also some with the light switch incorporated into the charging system.

Here is an article to help determine what you have and how to diagnose it.
3 brush generator

Here is another article.

Look over to the left column of the page under "articles". Lots of good info there. Also there is a JD specific board below.
generators

Here's yet another Charging Troubleshooting Procedure

John T
John Ts Troubleshooting

Lots of good information! Thanks for your help.

"<font color="#6699ff">[b:654c4848f0][i:654c4848f0]noticed the amp guage NOT working;[/i:654c4848f0][/b:654c4848f0]</font>"

Take a look at the diagram below for your Model A.





Note the white wire from the starter switch to the [b:654c4848f0]POSITIVE +[/b:654c4848f0] terminal on the ammeter.

Note the white wire from the [b:654c4848f0]NEGATIVE -[/b:654c4848f0] terminal on the ammeter to the middle [b:654c4848f0]BAT[/b:654c4848f0] terminal on the voltage regulator.

Take a look at the photo below.





If you put your test light on the NEGATIVE - terminal on the ammeter and the test light comes on, then current is flowing from the battery through the ammeter to the voltage regulator and the ammeter is working.

Take a look at the photos below of the voltage regulator and the generator.





"<font color="#6699ff">[b:654c4848f0][i:654c4848f0]with test light and engine running there are 2 big wires "hot" on the regulator;[/i:654c4848f0][/b:654c4848f0]</font>"

Yes, the two wires that are "[b:654c4848f0]<font color="#ff0000">hot[/b:654c4848f0]</font>" are connected to the [b:654c4848f0]BAT[/b:654c4848f0] terminal in the middle and the [b:654c4848f0]L[/b:654c4848f0] (lights) terminal on the left.


"<font color="#6699ff">[b:654c4848f0][i:654c4848f0]the third small wire is NOT hot.[/i:654c4848f0][/b:654c4848f0]</font>"

Correct, the third small wire connected to the [b:654c4848f0]FLD[/b:654c4848f0] terminal on the right is connected to the [b:654c4848f0]F[/b:654c4848f0] (field) on the generator.

Hope this helps.