Kubota Alternator/Volt Regulator

[CaveCreekRay]

I have an alternator putting out 18v and I think the voltage regulator is toast. (My battery shows 14v unloaded) Normally, new alternators have the regulator built into the back of the alternator. The L3800 alternator is $280-$320, the higher being dealer pricing. The voltage regulator doesn't even show up on the parts diagram.

Checking into the chance of getting the alternator re-built locally. Some Kubota alternators are on Amazon (Denso!!!) and run $75 with free shipping. Not this one! Oh well!!!

 

[Jim L.]

Sorry about your worries.

Wiring is making a good ground connection so that the alternator has a reference?

Possible to buy a new voltage regulator instead of replacing/refurbing the whole alternator. You're right about it not being in the IPL, but maybe the part number is on the regulator itself if you have time to open the alternator.

 

[CaveCreekRay]

Jim,

The dealer is going to test the alternator. If it is toast, I'll probably bring it home and swap it out with one I find online at about $50 less than dealer pricing. Part of that reasoning is to get the unit off and get a good look at it. You may be right: If that regulator comes off the alternator, I may be able to get a part number off it. In any case, having the old alternator in reserve would be a good thing if the new one eats a bearing in ten years.

I'll check the ground if they turn up a bad alternator. Hard to believe something electrical and so reliable could go goofy so young. I am hoping the battery is just acting goofy/toast.

We'll see.

 

[Apogee]

I second checking to make sure you have a good ground to it. On one of my older tractors the regulator is remote under the dash. The attachment bracket had broken and it was just hanging there. It received its ground through the bracket, so no bracket meant no ground reference. It had been overcharging batteries for years during its life with the previous owner.

Also, bring the alternator to a rebuilding shop. Usually, if its not a common unit, they will rebuild it for you for a lot less money than replacing it and they know where to find the correct parts.

Good luck!

Steve

 

[FTG-05]

Call these guys, maybe they can sell the regulator only and you can rebuild it yourself. Good luck! https://alternatorparts.com/#other

 

[CaveCreekRay]

Thanks to everyone!

Even the guy at the parts counter said I should try a local rebuild shop. I'll check alternatorparts.com to see if they have one. I hope to have the alternator checked out by the dealer soon but, either way, if its coming out, I am doing it.

We'll git her fixed up good!

 

[CaveCreekRay]

www.alternatorparts.com ROCKS!!!

$40-ish for a voltage regulator. Easy swap if it turns out to be the problem!

Gee.. I just saved my support $$ for this forum in one problem!!!

 

[CaveCreekRay]

Dealer called: The alternator is putting out a little over 14v under load, which is within the acceptable range of the alternator. I asked him how the battery sits at 14v and he said the battery checked out fine too.

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Good news is, I probably don't have to buy a new alternator. May be an intermittent ground that is currently grounded. But, at least I know that alternatorman.com has me covered should something develop in the future.

Question for the smart guys out there: If the volt regulator is inside the alternator housing, as opposed to under the dash like older models, how could a ground get loose? The case is grounded through the mounting bracket! Hmmmmmmmmm

Might even be a slight slippage on the belt.

-Why did I bother to take this thing in? Oh yeah: I thought the warranty covered it in the second year. DOH. Stupid me. XOXO to FTG-05!!!

 

[Orange man]

Just wondering why kubota would not warranty in second year?

 

[CaveCreekRay]

Dealer told me the second year was drivetrain only.

I just moved and can't find my warranty info... Is he incorrect?

 

[Orange man]

My new L3200 warranty book says 2 years on whole tractor and 3 years powertrain, maybe It changed but I do not think so.

 

[CaveCreekRay]

Yeah... I think in 2012, it was 2 years but he is saying the second year was drive train only. Anyone with a 2012 out there verify? It varies by model.

 

[Orange man]

I can not say for sure about a 2012, The new booklet says bx,b,and L series except landscape tlb. I would check with Kubota

 

[Jim L.]

I would keep an eye on this. It may not be out of the woods yet.

If it was really overcharging at a certain point the electrolyte gets hot and starts to boil off. Which is bad when the plates are not covered.

Loose or dirty connections to the battery could cause overvoltage because of bad sensing.

It is also possible that connections or wiring in the alternator could be moving as the tractor bounces around. On the bench that may not show up. You would be looking for loose bolts to the voltage regulator, field wiring rubbing, stuff like that.

If you get another overcharge situation, then after checking for loose external connections, the alternator would need to be opened for an internal visual inspection.

 

[Tooljunkie]

I think the voltage sense wire is going open, be it ign feed or a poor connection going to alternator. The alternator itself should be pretty well immune to vibration. A temporary wire from ign to alt ready to use if it starts doing it again.
I prefer to isolate the problem-100% positive before i start replacing or rewiring.

Could be something as simple as a loose connector or fuse for that matter.

 

[CaveCreekRay]

Warranty Note: I e-mailed Kubota for a link to my 2012 Warranty and they don't keep those available by e-mail! No .pdfs either! They are mailing me a hard copy of my warranty. Should be here in a few days. Guess that keep the confusion for new owners down to a minimum.

Good suggestions by all. Thanks. Slipping belt might be a cause too.

It's starting and charging OK for now. The dealer mechanic was pretty sharp and the battery is within 5 cranking amps of new so that seems allowable. Haven't checked the voltage since I got it back. They said the alternator is within the acceptable range. When I mentioned I would occasionally get the "CLACK" of the relay or the starter not making it fully into start mode, he asked me how long I run it after a start. His suggestion was to let it idle if you intended to sit for 5 minutes or less, rather than shutting it down. Repeated starts suck quite a bit of juice out of the battery, and its not a particularly large battery.

One weird thing was the 12v battery charger I put the battery on at night when I realized the battery seemed to be going. Its one of the small .5amp motorcycle battery keepers. It turns green when you get done charging and go to trickle. This thing used to go trickle in 30 seconds after attachment. Now, it takes 30 minutes on charge. I think that might be because the battery is slightly high on voltage and that might be goofing up the charger circuit until the battery settles down to a lower voltage.

One nice thing was the service writer told me over the phone that the general "overview" checkout went fine. He said the mechanic told him it was one of the "nicest" tractors they had seen come back as a two year-old and that made the hard work rebuilding it that much more rewarding. I told him what this poor thing had been through before I got it. He said, "Well you sure couldn't tell by looking at it now."

Tractors... what fun!

 

[Tooljunkie]

A battery that sees too much voltage will never go over 13.2 volts,2.2 volts max per cell. So if its getting hit with 18, it will boil the juice out. Also creating a highly explosive gas.

If dealer says its close to new battery voltage thats a good thing. Unless the tester is out of range. I just went through that with the charger/tester at work, reading a full volt high. Throws diagnostics right out the window.

Tested, sold,installed more batteries than i care to count.
There isnt much i havent experienced with your typical lead acid battery.

Shorted, open,sulphated, frozen,dry or exploded.
Not much else happens unless you drop it or it comes in contact with moving parts.


Glad its working now, lets hope it stays that way.

 

[Stubbyie]

Regarding the 0.5-amp trickle-type battery maintainer mentioned by the original poster.

I use a similar device on all my rolling stock.

Over time I've determined that when first energized (plugged in after use when parking) the charger will apparently 'sample' the battery with repeated short jolts.

As a result the red-yellow-green LEDs will light in sequence as the charger tests and thinks. It takes anywhere from 15- to 30-minutes for the charger to decide how it will charge the battery and then go into 'maintenance mode'.

Response to the electronic charger's 'testing' will vary by battery age and apparently by ambient atmospheric and operating temperatures.

Please post back your continuing experiences so we may all learn.

 

[CaveCreekRay]

Thanks again for the great suggestions!

I decided to go for a spell without any battery trickle charging. I have left the tractor idling for at least five to ten after each start, to recover the battery. So far, it seems to run normally. Extra time on the Hobbs meter but, hey, its not hurting anything.

I hadn't considered summer heat as a factor in the initial charger testing protocol. I am sure it affects how the battery responds to the voltage pulses. In the winter, the charger used to blink green within 30 seconds. Now, it may take 5 minutes.

And for ToolJunkie, I will try a different meter on it in the next few days to see what the charge and standing voltages are.

Stay tuned...

 

[CaveCreekRay]

WARRANTY CLARIFICATION-

After the dealer told me my second year warranty was drive train only, I called Kubota and they sent me a warranty for my tractor (sold 12-2012) and it clearly states:

-24 MONTHS or 1500 HOURS, whichever occurs first (for everything) and POWERTRAIN 36 months or 2000 hours, whichever occurs first.

However... Kubota has some pretty tight warranty repair criteria. My seat was locked all the way back and I couldn't get it to move. That was deemed "failure to maintain." (No regular lube by the previous owner) The voltage regulator check out was found to be normal. No warranty pick up for that because nothing was wrong. And, my seat switch frame was out of alignment (tweaked) and therefore considered a maintenance item. Maintenance is not covered.

There ya go!