Alternator wiring John Deere 3040

[otto1234]

Howdy,

Got an old JD3040 and I have alternator problems.

The alternator has 2 leads: a thick red one -I bet this is alternator output

and a more narrow gauge wire leading in to the cables entering the cabin.
I bet this is the field voltage.

This terminal reads zero volts when tractor is running. and I have battery voltage (12.3V) on t he alternator output so its clearly not charging.

Does anyone have a wiring diagram that shows where the field wire goes in the cabin?
I have problems tracing its origin and its got to be broken/disconnected/or...

thanks

Otto

 

[mddorange]

:welcome:
Welcome to the forum from Alabama. Sorry about your charging problem. How long have you noticed this problem?

 

[Zebrafive]

Small wire should go to your alternator/battery light. If alternator light bulb is burnt out system will not charge.

 

[jd110]

Small wire should go to your alternator/battery light. If alternator light bulb is burnt out system will not charge.

Most likely Zebrafive is correct. DOes your alternatorbattery light work in instrument cluster?