04 john deere charging bafflement

[Joe Cannon]

It could be that the alternator wire was rubbing the frame ...

 

[JRossiter]

Although you found the cause of your lack of charging, my friend just came up with a WSM.

For the future, here is the charging circuit.

The tractors wiring has about 8 diodes including V6

The safety relay K3 and its diode V6 is to protect the regulator from reverse battery polarity.

The WSM also comments:
Diodes usually fail in the open position but can fail shorted. If any problems in charging circuit check both V6 and V8 diodes.

I expect the relay would be the same as most automotive headlight relays.

I am surprised the relay was the issue as it is just a battery voltage sensing circuit carrying no real power that would burn the contacts.
Here is the list of relays:

K1 - Start Relay (SE1, W1)
K2 - Fuel Relay (SE2, W1)
K3 - Safety Relay 1 (SE3, W1)
K4 - Safety Relay 2 (SE3, W1)
K5 - Flasher (SE4, W1)

Do you need more help?

Dave m7040

Hi Dave, just a quick question. What is the purpose of the K4 safety relay? I swapped the K4 to the K3 connecror temporarily to verify that was my charging problem. As soon as I did that I was reading 14 V plus at the battery with the tractor running. PS, thanks for posting the wiring schematic.

 

[Dave M7040]

Hi Dave, just a quick question. What is the purpose of the K4 safety relay? I swapped the K4 to the K3 connecror temporarily to verify that was my charging problem. As soon as I did that I was reading 14 V plus at the battery with the tractor running. PS, thanks for posting the wiring schematic.

K4 relay is linked to seat switch to verify operator on tractor or fell off.

Dave M7040