John Deere 116 fails to charge battery

[EngineMan]

Info ask for....!

 

[EngineMan]

Going by the colour (green/black/red wire's in post #7) from the stator, it seem's to be the same has L100 so this may help...

 

[Rivets]

Thanks EngineMan.

 

[Mtn.Mike]

My apologies for not getting back sooner. My router got "fried" in a recent thunderstorm. I removed the battery from the tractor after starting it a few times and placed it on my automatic charger over night.
When I came back the next morning it had failed to charge beyond 12.59 volts and the code was telling me the battery got too hot.
According to my manual this might have been caused by a bad cell in the battery. All I have to test the load is an automobile battery load tester so I tried it.
As soon as a load was placed on the battery it showed weak.
Could my problem be a bad battery?

Thanks for all the responses and diagrams. I am printing them out for further reference.


Mike :thumbsup:

 

[Rivets]

That's the first place I would start.

 

[Mtn.Mike]

Well I put the new battery in and no change. The electrical system still doesn't charge the battery. I checked the output of the black (from stator) to green to red wire and it was between 15.8 and 16 volts AC.
I will check the red wire going into the module to see if it's the same.
If so would that indicate that the diodes in the module are bad since it appears that there is no DC voltage from there to the battery.
My understanding is the module converts the AC to DC which charges the battery. Is this right?
I will update as to my progress.


Mike :confused2:

 

[Rivets]

I don't think you tested AC voltage right. Look at the instructions EngineMan posted. Output voltage AC test goes from stator output wire to ground.

 

[Mtn.Mike]

I put the meter on AC and with negative lead grounded on the engine and positive lead on the wire from the stator I measured the AC voltage.
Did I do this wrong?


Mike

 

[Rivets]

No, that is correct. Just follow the steps listed in post #11. They will walk you through it. Then post back what happened at each test.

 

[Mtn.Mike]

Well I checked the voltage from the stator and it's around 38 volts. This wire then goes into a module that contains four wires. I think this part number is AM 38571. I'm unable to find a way to check this module while the tractor is running since it's located under the battery.
Is it possible that this module takes the place of a rectifier and there is a faulty diode in the module since I can find no regulator/rectifier anywhere?
How can I check this module on the workbench?

Thanks, Mike