B 1500 Boiling Battery

[Crashcage]

Hi all,
As the title says,was doing some work and the charging light came on,carried on as i thought it was maybe the fan belt,it has done this before and the light went out a bit later.
Lifted the hood when i stopped expecting to see a slack fan belt,was okay.On inspection the battery was boiling.
Now this had happened on my Motorcycle,and it was the reg/rectifier.
Took off the steering wheel and lifted the instrument cowl.I have found the reg/rectifier,4 leads coming from it.There is also a black box.
I have downloaded 4 different manuals,owners 2x B1200-1900,a B6200-B7200 and wsm B6200HST-B7200HST.
For the wiring diagrams,but none look the same,or have the right colour coding for the wires.All of them show the dynamo has 2 wires coming from it,mine has 3.
There is a Brown wire with a white stripe,this goes to the Reg/rect,but it also goes to the black box.
Confused i am.

 

[Dave_eng]

you need to look at much older Kubota wiring diagrams to see a three wire dynamo.

I have attached a wiring diagram from a B6000.

In the early years Kubota ran the lights from two of the dynamo wires. The lights ran on alternating current and would get dim or bright based upon engine speed.

Another pair of the three dynamo wires would go to the regulator/rectifier to charge the battery. This pair would go directly to the light switch.

Owners of this vintage of tractor suddenly learned of this old design when they bought LED bulbs which would not work on the alternating current provided to the bulbs.

Until you can post a photo of the other black box I cannot guess what it is but it will not have anything to do with the charging system.

Early Kubota's also did not have charge warning lights hence the limited number of wires on the regulator.

To start troubleshooting first, using an alternating current volt meter, check the voltage between all three dynamo leads with the wires disconnected.

Dave

 

[torch]

Boiling generally means the battery is being over-charged. That suggests that the regulator is bad.

Kubota offered a "Large Capacity AC Dynamo" as an option on some alternators. The one for my B7100 shows 3 wires (Red, White with Black stripe, White with Green stripe) and the installation instructions indicate the stock regulator is abandoned, replaced by a new regulator unit that looks to have 6 wires (White, White with Black stripe, White with Green stripe, and 2 of Black with Red stripe). Those last two go to a charge light. Maybe yours has a similar optional high-capacity unit?

 

[Crashcage]

you need to look at much older Kubota wiring diagrams to see a three wire dynamo.

I have attached a wiring diagram from a B6000.

In the early years Kubota ran the lights from two of the dynamo wires. The lights ran on alternating current and would get dim or bright based upon engine speed.

Another pair of the three dynamo wires would go to the regulator/rectifier to charge the battery. This pair would go directly to the light switch.

Owners of this vintage of tractor suddenly learned of this old design when they bought LED bulbs which would not work on the alternating current provided to the bulbs.

Until you can post a photo of the other black box I cannot guess what it is but it will not have anything to do with the charging system.

Early Kubota's also did not have charge warning lights hence the limited number of wires on the regulator.

To start troubleshooting first, using an alternating current volt meter, check the voltage between all three dynamo leads with the wires disconnected.

Dave

Will upload photos tomorrow,thanks for your reply.
Think the regularor has already been changed,as it looks like a Mosfet one fitted to M/cycles,alluminium ribbed for cooling,blach box has no identifying numbers.But has a lot more wires.

 

[lugbolt]

You need to know what kind of voltage is being forced into the battery by the reg/rectifier assembly. Without that data, it cannot properly be diagnosed.

 

[Crashcage]

Okay,got some photos sorted.Resized,and tried to upload,but its not happening.
Pressed upload and screen goes to white,mozzila page and cant find them on here,am i missing something?

 

[North Idaho Wolfman]

You using the paper clip (Manage attachments) and trying to upload one photo at a time?

 

[Crashcage]

You using the paper clip (Manage attachments) and trying to upload one photo at a time?

Whats paper clip?
Was trying to attach them.

 

[Crashcage]

Found what you meant,same result.
I press upload and it goes blank.Could it be Mozzila?Or AVG ?
Old fool here
Thanks for your reply North Idaho Wolfman
Will keep on trying.

 

[Dave_eng]

Found what you meant,same result.
I press upload and it goes blank.Could it be Mozzila?Or AVG ?
Old fool here
Thanks for your reply North Idaho Wolfman
Will keep on trying.

As a quick fix, I will send you my email address in a private message.

Send me the photos you have and I will put them up

Dave

 

[Crashcage]

As a quick fix, I will send you my email address in a private message.

Send me the photos you have and I will put them up

Dave

Great,thanks Dave.
I have resized them.

 

[Dave_eng]

This are the photos sent to me by the owner of the boiling battery tractor.

I had to shrink his emailed photos to 30% to have them work.

It would be helpful to have a more overall view of the both sides of the engine.

Dave

 

[Crashcage]

This are the photos sent to me by the owner of the boiling battery tractor.

I had to shrink his emailed photos to 30% to have them work.

It would be helpful to have a more overall view of the both sides of the engine.

Dave

Thank you Dave,
Will send more photos.
Will try and post with smaller kb,saw that max size was 195kb so kept them under that.But will make them all around 50kb.

 

[Crashcage]

Pics of the tractor as requested.

 

[Dave_eng]

I am a bit puzzled by what your tractor has.

Not like any I have seen in North America.

The black box is described as a regulator relay. I don't know what it does as I cannot find a wiring diagram.

I can find it on ebay.co.uk.

https://www.ebay.co.uk/itm/67311-55...ispr=1&hash=item41e8c68dbc:g:VXkAAOSw66NbXoi2

I can find a regulator/rectifier on ebay.co.uk which looks identical to yours.

https://www.ebay.co.uk/itm/RECTIFIE...684247?hash=item469d4b8a57:g:vuIAAOSwepJXZRDH

Perhaps from your current location you can search for wiring info in Asia.

Replacing the regulator rectifier seems like a first step. But I cannot say this with total confidence that it will solve your problem. Perhaps the job of the relay is to switch more of the dynamo output into use as needed but again a big guess.

Dave

 

[torch]

That looks like stock dynamo, not the optional "large-capacity" unit that I am aware of.

I suspect the 4-wire regulator is the original and that a previous owner tried to McGuiver that aftermarket unit because of a problem with the charging system.

I would start by measuring the DC voltage at the battery with the engine running (top off the electrolyte level first!). If it's over 14.5v, then the system is indeed overcharging the battery.

Then disconnect the 3 wires from the dynamo and, with the engine running, check for AC power between each in turn. IE : 1-2, 2-3, 1-3 and see which pairs have power between them.

If the dynamo is working and if the system is as the diagram that Dave posted, you should find that at least two pairings produce voltage -- probably 20 or 30 vac.

However, you mention a 'charge light'. Dave's diagram does not provide for one, and usually such a light indicates a lack of charging, not an overcharging. Three possibilities spring to mind:

1. Your wiring is different than Dave's diagram.
2. Someone added a charge light when they made the other modifications.
3. You are mistaking the low oil pressure light for a charge light.

It would also probably be worthwhile to look at the back of the lights switch to see if it has the extra terminals and wires shown on Dave's diagram or if it is a simple on-off switch. That would be another clue.

 

[Dave_eng]

I think the three wire dynamo wiring diagram I posted is only correct as far as the three wires are concerned.

Because I can find the two components ( the relay and regulator) on eBay UK, I do not think the B1500 tractor's wiring has been altered.

The relay may be involved with the no charge light.

Dave

 

[torch]

I don't think I've ever seen a charging system with two separate regulators before. Separate regulator and rectifier, yes. But not two regulators.

 

[Crashcage]

I don't think I've ever seen a charging system with two separate regulators before. Separate regulator and rectifier, yes. But not two regulators.

Apologies for my absence.Working away at the moment and only get to net when i am home.
That is what confuses me!Why 2 regulators?Seems overkill!
My vehicle electrical exp mainly comes from motorcycles.As i mentioned earlier i had the same problem with my KTM990SM.Got home,bike had been running strange.Got off and steam,smoke coming from under the seat.Whipped the seat off,and the battery was all swelled up,dont know why cos they have a breather tube!?
Anyway,replaced reg/rectifier with a generic Mosfet Reg/Rec and new battery,jobs a good un!
I will make more photos of the wiring.
Thinking about it,its a diesel.Only needs battery to start.
Then i suppose,power to the hrs counter,lights,indicators and horn.
Seems what i have is very over complicated!

 

[Crashcage]

Well,I checked out the links .Thank you for them.
One of them,from Greece wants 78GBP And 32 GBP postage????WTF!
Gonna run my tractor with a slave battery,its Diesel right??
Feck these idiots,with high postage charges!
I will find another way!!
Thanks to all who commented,and gave advice!In this time of covid19,we all need to be planting!!!!
Thanks once again!