Alternative regulator?

volp

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Equipment
Kubota B6001, MF35 with backhoe, Ford 3000, JD LX186 Lawn tractor
I have a B6001 with a D950 engine. It is not charging the battery. I have not yet tested the alternator (dynamo) but I suspect that the regulator is bad. When looking at prices for a new Kubota regulator I found these pretty high! :eek:
Are there alternatives to the Kubota regulator?
I was thinking of replacing it with a rectifier bridge and a solar panel regulator which I can get at a much lower price.
Anyone out there with more knowledge of electronics who can say if this is a good or bad idea? Or have a better proposition?

Anders
 
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Jim L.

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Jun 18, 2014
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When you test the alternator, try to see if it is the windings, rectifiers, or regulator.

If it is the rectifiers or regulator, see if the markings are still visible. These parts may be cross-referenced to a replacement. Kubota buys these on the open market, so they do not have to be "Kubota."

If the windings, a shop may be able to rewind the alternator.

For myself, I would not use a solar regulator. They do not meet the requirements for vibration on a tractor.

If the connections are bad, the alternator will show bad. Also, if the battery is bad, you can get bad readings on the tractor.
 

Dave_eng

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From looking at an on-line wiring diagram for a B6001 it looks like only two of the three leads from the alternator go to the rectifier. The third alternator output goes to the light switch which makes me think that the lights are running on alternating current and change brightness based upon engine speed.
Having the alternator tested at an independent repair shop, if you don't know how to do it yourself, would be the first step before creating a new rectifier.

Do your headlights work? Do they change intensity as the engine speed increases? This would be a clue to show if the alternator is working.

If I was going to try and jury rig something, I would be looking for a rectifier for a kohler engined riding mower. It would be set up to rectify three alternator leads but would work if you only used two of the three inputs.

Dave M7040
 

volp

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Equipment
Kubota B6001, MF35 with backhoe, Ford 3000, JD LX186 Lawn tractor
Thanks for the replies.
I started with disconnecting the alternator (dynamo) an measured the output. At high speed it varied between 30 and 40 volts which should be OK.
Then I removed the rectifier from behind the dashboard and measured continuity in the two leads from the alternator. Only one lead had continuity. Then I saw that there was another connector which was not connected to the alternator. This one showed continuity to the rectifier! :) So I used this instead and got charging! :D
I am however worried that there is no regulator only a bridge rectifier what I can see. :confused: One explaination could be that the old engine had only a low output dynamo in the fan so there was no risk of overcharging the battery. The D950 engine have a dynamo with larger capacity (about 14 amp) and therefore might need a proper regulator?
Any thoughts?

Anders
 

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Jim L.

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If you can find an automotive external voltage regulator, at the price you want, that would be a better option.

The solar panel charger will work. If you do not use the tractor often, then it will be an option.

When you add your regulator, it will be easier to maintain if you add a connector. Use only stranded wire, not solid.
 

volp

Member

Equipment
Kubota B6001, MF35 with backhoe, Ford 3000, JD LX186 Lawn tractor
I tested the rectifier today and as suspected the voltage rose to 16 volt with the battery connected which is to high.
When I turned on the headlights it came down to around 14 volts.
Therefore it seems necessary with a regulator so I ordered a voltage regulator with rectifier for Onan John Deer 318-420. This is good for 20 ampere and set at 14.4 volts. I found it on Ebay for US $ 21.

Anders
 

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Jim L.

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Jun 18, 2014
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The amount of charging current into a battery will vary with the amount of discharge. A 90% charged battery will allow less charging current than a 70% charged battery.

However, a battery that has been neglected will lose capacity. It will stop taking a charge way below its listed capacity.

It's difficult to tell the battery health from only the charging current. A battery load test or even a hydrometer gives additional information.
 

ShaunBlake

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I have a B6001 with a D950 engine. It is not charging the battery.
... Then I saw that there was another connector which was not connected to the alternator. This one showed continuity to the rectifier! :) So I used this instead and got charging! :D
Anders, I'm puzzled by this -- you haven't said anything about what might have caused the problem, or how long it could have gone unnoticed. Was there something that was done that may have pulled that wire off (or moved it to the wrong post)?

Do you plan to take the battery out to be load tested, or just wait and see if it will maintain a charge and fluid level?
 

volp

Member

Equipment
Kubota B6001, MF35 with backhoe, Ford 3000, JD LX186 Lawn tractor
Anders, I'm puzzled by this -- you haven't said anything about what might have caused the problem, or how long it could have gone unnoticed. Was there something that was done that may have pulled that wire off (or moved it to the wrong post)?

Do you plan to take the battery out to be load tested, or just wait and see if it will maintain a charge and fluid level?
ShaunBlake, I have no idea how long time it was unconnected! :confused: I suspect that it happened when they changed engine not long before I bought it. :eek:

Anders