Battery/Charging problem

[Henniker]

Battery/Charging problem.

Man, it was a rough winter. I had to replace the batteries in my snowmobile, my car, and most recently my tractor.

I bought the replacement batt from the dealer, so although it was a different brand, I have to assume it's a proper replacement.
After I installed it, I started the tractor (A Kubota B2710) and let it warm up just to check for any problems. NONE FOUND.
Easiest repair I've done in years. Thought I was golden....

Two weeks later, I started it up, and the battery (charging) light stays on!
Since the tractor started fine, I didn't suspect any connection problem at the posts, but I took them apart, cleaned and re-set them anyway.
No difference.
I even tried changing the position of the battery Tender cable from inside the clamp to outside (since my poor tractor lives outdoors, I keep it on a battery tender).

Increasing the RPMs doesn't seem to make a difference, (but I'm not sure at what RPM the alternator starts to charge).

I don't think I dislodged any cables during battery changeover. There only seems to be one big cable at each terminal.
Has anyone had this experience?
Could I have blown my voltage regulator during changeover (and where is it? and how do I test it?)
I find it hard to believe that my alternator suddenly crapped out after I changed the battery....(Buy maybe??)
There is only one wire from the alternator. Should I be getting 12V from there to ground? (And if not=bad alternator?)
Although I didn't adjust it; I even checked the belt tension. Seems OK to my inexperienced hands.

If anyone has any experience or advice on this issue, I'd sure appreciate your input. Thanks!!

 

[George2615]

You should get a reading from the large terminal on the alternator to ground. Use your meter to check battery voltage when not running. Should be at least 12V. Then start the tractor and read it again. If the alternator and regulator are working it should read above 13V. If not either the alternator or regulator has failed which is probably why your light stays on. Not familiar with your tractor whether it has the regulator built into the alt. or if it's a separate unit. I suspect it's built into the alt. If this is the case it can be rebuilt by a starter / alternator repair shop.

 

[number two]

Your B2710 would come with a dynamo,a generator of sort with an external regulator and wiring I'm not really familiar with.
It certainly sounds like coincidence is the case here,your tractor is not charging.
The stock dynamo produces about 14 amps,adequate unless you're running extra lighting,etc.
An upgrade alternator kit has been(and may still be)available for about $200.
Should you happen to have the alternator,the diagnosis procedures will differ.
Most certainly our expert members will post the procedures and pictures of the dynamo and alternator so you can determine which one you have and diagnostic steps as well.
Depending what you find and you indeed have the dynamo,it may make sense to install an alternator kit.
Good Luck!
Let's remember what Memorial Day is all about!

 

[Sodo]

A year later,,,,

I have a 2710, same problem. I disconnected the dynamo, and put an AC multimeter across the two blue wires. Low RPM it's 13v, and high RPM it's 27 volts. I did not connect a load across it, but I will try that next. Plan is to use two 12v 55watt car headlights in series (a 24v load appx 5 Amps) for this test.

Will this tell me if the dynamo is OK?

And if its the regulator, does anybody know where I can locate the regulator on a B2710? (or a b7600, 7800 or other similar)? Could be under the dash but it's kind of a hassle to get in there to look.

 

[Sodo]

OK since I have 27vAC coming out of the dynamo, I'm checking the regulator.

I pried the dash off and found the regulator under the dashboard. Mice had nested there and corroded the connector to the regulator. To the point where the red wire's terminal 'broke'! And I can see where it was sparking, blackened the plastic.

I removed it from the connector and bypassed it with new spade terminals and all is good. Charging now at 13.4v.
:thumbsup: