Battery light coming on

[JD 1250]

I have a Kubota B2910 with a 72 inch mid mount mower. The tractor has 1762 hours on it. I mow around 8 acres of hills and flats.
While mowing for a few hours, at 2500 RPM, the battery light comes on. It will stay on for about 20+\- minutes and then goes back off. All of this is intermittent. The first time I noticed it, I tightened the belt tension. The light turned off and after 30 minutes or so, it was back on and off sporadically. I ended up putting a new belt on it and it痴 back to doing the same thing as with the old belt. I did the no load test on the dynamo at idle with a reading of 14.8 volts and at high idle (2500RPM) with a reading of 31.3 volts. Then took a reading at the battery at 2000RPM with a reading of 12.1 V.
My question is, is this a common issue with this model tractor? If not, what else should I look for?

 

[Gator6x4]

I have a Kubota B2910 with a 72 inch mid mount mower. The tractor has 1762 hours on it. I mow around 8 acres of hills and flats.
While mowing for a few hours, at 2500 RPM, the battery light comes on. It will stay on for about 20+\- minutes and then goes back off. All of this is intermittent. The first time I noticed it, I tightened the belt tension. The light turned off and after 30 minutes or so, it was back on and off sporadically. I ended up putting a new belt on it and itç—´ back to doing the same thing as with the old belt. I did the no load test on the dynamo at idle with a reading of 14.8 volts and at high idle (2500RPM) with a reading of 31.3 volts. Then took a reading at the battery at 2000RPM with a reading of 12.1 V.
My question is, is this a common issue with this model tractor? If not, what else should I look for?

Check the voltage in and out on part number 30 in the diagram. https://f01.justanswer.com/koboma/e51d4889-fab5-4a0a-8714-eb5bb18bebf5_B2910+voltage+regulator.pdf

 

[Roadworthy]

Knowing nothing about your tractor but based upon past automotive experience my guess is either the brushes in your alternator or the voltage regulator. Most likely to me would be the brushes - they wear out.

 

[seville009]

How old is the battery? If it were me, I’d change that out first if it’s old, as that might solve the issue.

 

[moship]

The OP describes a voltage pattern that proves the dynamo (not alternator) is functioning correctly, but doesn't provide proper voltage to the battery. The most likely culprit/solution is as Gator6x4 suggested above in post #2. It's also possible one of the wire or wire connections is faulty, so I'd investigate that first before buying a new part.

Buying a battery before fixing the problem will likely result in killing a perfectly good battery.

Good luck and post back the fix.

 

[JD 1250]

Battery is almost 2 years old. I will check all connections and let you guys know what I find. Thanks for all the information

 

[Fallon]

I'll 2nd fixing the problem that is likely to kill a new battery. Voltage regulators are close to wear items.

 

[JD 1250]

I believe I have located the problem. I pulled the regulator plug from the wire harness plug and it is partially melted. The black wire is the one that is melted. Worst part, not only is the regulator plug bad, the wire harness plug is also bad. I guess it is not possible to purchase the plug end only for the main wire harness?? I guess I will have to rig something up for it. Any suggestions?