Not charging

[Bob trike]

Hi all. I have an 04 B21 Kubota, with 245 hours. It is not charging. I took the alternator and had it tested. It was fine. I checked all the fuses and they look good. It will turn over and start if I jump it. It looks like with the key on I do not have power to the plug that goes into the alternator. What is next, the ignition switch? Can anyone help. Thank you.

 

[RustyA]

Is the voltage regulator internal to the alternator or external? If external it may not be telling the alternator to charge? With tractor running you should be reading 13.6-14.2 volts at battery with a good alternator and regulator. If it's in that range running your battery might have a bad cell? Fully charged battery should test for 12.4-12.8 volts at rest.

 

[WranglerX]

Does your dash have a ALT lamp?.... IF it does, check it... It usually supplies 12 volts to alternator (through bulb) to initialize the alternator to start charging on start up....

 

[Bob trike]

Is the voltage regulator internal to the alternator or external? If external it may not be telling the alternator to charge? With tractor running you should be reading 13.6-14.2 volts at battery with a good alternator and regulator. If it's in that range running your battery might have a bad cell? Fully charged battery should test for 12.4-12.8 volts at rest.

Thanks for the reply. The regulator is part of the alternator. The battery tested good, but is down a bit at the moment.

 

[Bob trike]

Does your dash have a ALT lamp?.... IF it does, check it... It usually supplies 12 volts to alternator (through bulb) to initialize the alternator to start charging on start up....

Thanks for the reply. I know there is a light but I don’t think it was ever on. So the bulb has to be good so the current goes through it? I will go out and check it And come back.

 

[Roadworthy]

When you turn on the key your alternator and oil pressure lights should go on - it's a bulb check. When the engine starts they should go out which shows your alternator is charging and your oil pressure is up. Try cleaning battery terminals and connectors, then tighten securely. Don't overlook the point where the ground wire connects to the frame.

 

[Bob trike]

So I just took the dash apart and it doesn’t have a bulb for the alternator power to go through. I have 12 volts at the power stud on the alternator, but the small white plug that goes into the back that should have power to both prongs has none. Where does it get power from?

 

[Bob trike]

When you turn on the key your alternator and oil pressure lights should go on - it's a bulb check. When the engine starts they should go out which shows your alternator is charging and your oil pressure is up. Try cleaning battery terminals and connectors, then tighten securely. Don't overlook the point where the ground wire connects to the frame.

Thanks for your reply. The tractor will run if jumped. The headlights work. There is power to the alternator on the big stud on the back. Just none to the small white plug that goes into it. I need to trace that back to wherever it comes from. It doesn’t look like much coming from the ignition switch. Where does the power come from?

 

[sea2summit]

Just to confirm you're not on the original battery/you know the battery is good?

 

[Thomas]

Check for rodents that might slighty chew wire.