Battery not charging

[newshb_k]

Hi

I have kubota b7100 (none-HST), and the battery doesn’t charge; even with high revs

if I remove the battery cables after starting the tractor, it will keep running.

The battery is almost new, so I suspect it could be bad wiring, and not sure if it is the regulator

I took a look on the wiring diagram, and I am planning to check the wiring from the generator to regulator, then regulator to switch, and then from the switch to engine/battery

Is that what I am supposed to check

 

[North Idaho Wolfman]

You will need a multimeter and set it for AC, disconnect the 2 wires off the generator / Dynamo.
Connect the meter to the 2 wires off the gen /dyno and run the tractor, you're looking for about 15 VAC in idle and about 30 VAC full throttle.

 

[newshb_k]

You will need a multimeter and set it for AC, disconnect the 2 wires off the generator / Dynamo.
Connect the meter to the 2 wires off the gen /dyno and run the tractor, you're looking for about 15 VAC in idle and about 30 VAC full throttle.

thx

so I disconnect the 2 wires of the dyno when tractor is off, and once I connect the meter, I start it and see the reading?

Also, since the tractor keeps running if I disconnect battery, doesn’t this mean dyno is ok?

 

[North Idaho Wolfman]

Also, since the tractor keeps running if I disconnect battery, doesn’t this mean dyno is ok?

No, diesels do not need electric to run, they make the heat to fire off of compression not electric.

 

[85Hokie]

AS Wolfman said - the battery serves only one purpose there - TO START the engine - once running the battery simply sits there and get charged in a perfect world.

SO - the two wires - get your meter and set for AC - and then use a clip or get someone to hold them on the two leads, it DOES not matter what wire to red or black leads - fire up the tractor, there should be a reading of AC voltage - and slowly rev it up, the voltage should climb WITH the rpms. As mentioned, at near WOT you should be getting upwards of 30 volts AC.

NOW - if that checks out - the next part of the puzzle would be the VR - voltage regulator, that little box flips the AC back to DC and charges the battery.

The chances of the Dynamo being bad are very slim - it is such a simple device that it can almost never be bad - ( could have a broken wire)

Does your B7100 have 4 bolt front wheel or 6 bolt?

 

[newshb_k]

AS Wolfman said - the battery serves only one purpose there - TO START the engine - once running the battery simply sits there and get charged in a perfect world.

SO - the two wires - get your meter and set for AC - and then use a clip or get someone to hold them on the two leads, it DOES not matter what wire to red or black leads - fire up the tractor, there should be a reading of AC voltage - and slowly rev it up, the voltage should climb WITH the rpms. As mentioned, at near WOT you should be getting upwards of 30 volts AC.

NOW - if that checks out - the next part of the puzzle would be the VR - voltage regulator, that little box flips the AC back to DC and charges the battery.

The chances of the Dynamo being bad are very slim - it is such a simple device that it can almost never be bad - ( could have a broken wire)

Does your B7100 have 4 bolt front wheel or 6 bolt?

Thanks a lot for the detailed answer, I well check the dyno, and proceed forward in troubleshooting

mine has 4 bolts front wheel

 

[North Idaho Wolfman]

Does your B7100 have 4 bolt front wheel or 6 bolt?

All B7100DT's had 4 bolts, never six, unless someone got inventive and swapped axles form a newer HST.