2920 died while working no power

[Henro]

This is just speculation but my experience with my Kubota tractors is that dynamos were rated lower than the alternator option as far as power output goes, and the 40 watt(edit: Amp, not watt) alternator was an option, which I purchased.

My guess would be, since your problem went away with the battery change that the problem was within the battery, and somehow the failed battery was loading down the dynamo, and therefore the dynamo output voltage dropped below the level needed to keep the fuel cutoff solenoid energized, so fuel was cut off.

There are two electrical schemes used by Kubota for fuel cutoff to shut down the engine with the key. One is they use a timer relay, and apply voltage to the fuel shutoff solenoid for several seconds when the key is turned to the off position. The other is the cutoff solenoid has two coils, and one is kept energized to keep fuel flowing through the injector pump, and a spring pushes the solenoid armature to cut off fuel when the key is turned to the off position, and voltage is removed from the solenoid.

IF you tractor has the second scheme, like my BX2200 does, then if voltage dropped for any reason the engine will shut down. But it will start if jumped, because the battery supplying the voltage is strong. But as soon as the jumper battery is removed the engine will shut down again.

That is my guess...based in some fact...don't know your tractor though...

 

[Henro]

Just an afterthought. If the above scenario is the actual case, then you may be fortunate that the tractor did not continue to run, with the dynamo overloaded. It might have over heated and failed, and you would have needed to replace it along with the failed battery...

 

[Freddieboy]

An old style diesel will run without a battery or any electrics at all.

Newer diesels - those built in the last 10/20 years depend on some source of electricity to run things like a fuel solenoid, lift pump, and computer. They won't run if a short circuit is drawing all the current from the dynamo.....leaving none for the tractor.

It's rare for a battery to fail because of has short-circuited internals, but not impossible. More probably the battery leads shorted. Either would cause the tractor to stop and not restart. Sounds like something like that is what happened.

rScotty

Thx for the input on this....

 

[Freddieboy]

Just an afterthought. If the above scenario is the actual case, then you may be fortunate that the tractor did not continue to run, with the dynamo overloaded. It might have over heated and failed, and you would have needed to replace it along with the failed battery...

Thanks for the info and very helpful to understand this.