JD 4110 won't charge battery

[driscollt]

I have checked the alternator and it has a good battery.

Replaced the voltage regulator and start switch (ignition/key switch).

Symptoms - no light for battery when key switch is in Run

Battery runs down when tractor is used but starts with no problem.

I have replaced the bulb for the battery discharge indicator.


Thoughts?

Thanks

 

[Coyote machine]

Charging circuit is not working. You're running off your battery until it's dead. You need around 14.25- 14.5 volts at the battery when the tractor is running - what is it reading?

 

[DFB]

Unplug the wiring harness from the glow plug timer and see if voltage comes up.

 

[driscollt]

Yes, the voltage at the battery is around 12.5. I have tested the alternator per the shop manual and it appears to be working as well. The battery charges normally. I have replaced the voltage regulator. The alternator on this unit is a 20A alternator. I have done quite a few of the tests and have not located a problem. Why does the alternator light not come on? Thanks for the response.

 

[driscollt]

Not sure what the glow plug timer looks like? I can try that when I get home tonight. Can you give me some detail? Thanks

 

[DFB]

There is a small plastic box mounted on bracket over the radiator. There will be a plug in harness just disconnect it from the module. If the timer goes bad it can draw a continuous current to the glow plugs while the tractor is running and the alternator is unable to keep up and recharge the battery. Tractor still will operate fine without timer plugged in circuit. You can manually activate the glow plugs still by overiding the start circuit pull up pto switch or put range selector in gear and turn key to start. It is fairly expensive part to replace.

 

[driscollt]

There is a small plastic box mounted on bracket over the radiator. There will be a plug in harness just disconnect it from the module. If the timer goes bad it can draw a continuous current to the glow plugs while the tractor is running and the alternator is unable to keep up and recharge the battery. Tractor still will operate fine without timer plugged in circuit. You can manually activate the glow plugs still by overiding the start circuit pull up pto switch or put range selector in gear and turn key to start. It is fairly expensive part to replace.

That makes sense - I will check it out when I get home. Thanks for the info.

 

[driscollt]

Well, when I disconnected the relay completely - the tractor would not start. I had to leave 2 of the 3 leads and then it would start. Either way, no increase in voltage at the battery. I probably will need to replace it to see if that is the issue. Anything else I can check? or ideas? Thanks

 

[joecdeere]

I have a PDF of the Deere Tech manual you're welcome to. If wanted shoot me your email

Joe

 

[driscollt]

Thanks but I have the manual. It covers a lot of things but not everything!

 

[Rocky Hoffler]

Most of the time the alt light only comes on if alt is not charging previous post suggest to look at glow plug circuit if it has greater draw than what alt will put out it like having money in bank and wife is taking out more than you are putting in you go broke after a while. alt light should light when eng off and key is in run position most of these have a terminal on alt that runs light check and see if wire has came off of terminal.

 

[Tx Jim]

Is alternator belt snug?

 

[Zebrafive]

You stated the battery/alternator light is not working. Also you replaced the bulb. So no light when turning key to ON for bulb check? If so you need to find out why. Normally the 12volts to the battery/alternator light is what excites the alternator to start it charging. When charging the alternator voltage cancels the battery voltage to the light and it goes out.

 

[Zebrafive]

I have a PDF of the Deere Tech manual you're welcome to. If wanted shoot me your email

Joe

Can you post the charging system wiring diagram? If not PM me for email for tech manual PDF

 

[joecdeere]

 

[DFB]

Faulty diodes have been the cause of many a problem. The earlier models, mine included didn't have them. I'm curious though to see the glow plug circuit diagram on a 4110

 

[joecdeere]

 

[DFB]

Thks for that post!

 

[Zebrafive]

Thanks for the diagrams. The battery light is not wired as I thought.

 

[Topher265]

Well, when I disconnected the relay completely - the tractor would not start. I had to leave 2 of the 3 leads and then it would start. Either way, no increase in voltage at the battery. I probably will need to replace it to see if that is the issue. Anything else I can check? or ideas? Thanks

Replacing parts to see if that is the problem is not the right way to fix the problem.

It sounds like two different problems. No battery light comes on, and the alternator is not charging.

First check the fuses/diodes.

I would then suggest a simple test: unplug the voltage regulator (VR) and use a jumper to get 12v to the 605 circuit - blue with a white tracer. Doing this should turn the bulb on. If it doesn't, there's a problem in that small circuit. Fix the problem so that the bulb turns on when it should.

If the battery is showing 12.5V when the tractor is running, the alternator is not charging the battery. If it was, when running there would be 14.0-14.5V across the battery terminals. But the OP tested the alternator by itself, and it "appears to be working". Also, the VR was supposed to have been replaced...even though it may not have needed replacing. Could the VR have been installed/connected incorrectly?