Kubota L4610 electrical problem (need help please)

[Kubotajoe99]

My L4610 won't charge my battery. About 6 months ago the alternator went out and I took my tractor to the local mechanic and he ordered and replaced the alternator. All worked fine for 6 months, then after using my tractor for a couple of hours the other day, I turned it off and tried to start it again within a couple of minutes and the battery was dead. I was able to jump start it take it back to the mechanic. He replaced the alternator again (2nd one in 6 months). After getting it back from the mechanic yesterday, I used it for about 2 to 3 hours and turned it on and off 5 or 6 times, then one time it was totally dead again. The battery is 2 years old and will take a charge and tested good. The mechanic said I need to have the RPMs at 2000 to charge the battery and that it could charge as low as 12.5 volts on a diesel tractor. I'm only seeing about 12.6v at the battery at 2000 rpm. At an idle the voltage at the battery is about 11.9 to 12v. The alternator model is 12179N. Is the voltage at the battery to low? Is that the correct alternator? Is there a separate voltage regulator or is that inside the alternator? Any help would be greatly appreciated.

 

[grsthegreat]

Did you have the battery bench tested under 50% load?. I hardly run my tractor at 2000 rpm….usually at 1800 unless im moving dirt. Mine always charges.

when it refuses to start, is it completely dead or does it try to rurn over slowly. You could have bad battery cables or bad grounding issues going on.

 

[Kubotajoe99]

I'm not sure how the battery was tested, probably not a rigorous test. I also don't normally run at 2000 RPM. I've owed that tractor for 20 years and usually run between 1400 and 1500 RPM and never had a charging problem until 6 months ago. I'm thinking it might be the wrong alternator, a bad battery, or maybe glow plugs draining the battery?? When it won't start, it is totally dead. Jump starts from car easily.

 

[Root Cause]

I just had an electrical issue. It is frustrating. If you are waiting for service, put your frustration into something that costs nothing and might help.

Get some wrenches, sandpaper, and dielectric grease and clean up both ends of the positive and negative cables.
It might be that you have more than one issue and you get lucky. At the least, you have eliminated corrosion as a potential problem.

I found corrosion on the positive terminal, cleaned it up and it ran fine that day. Then had more issues the next week. Turned out to be more corrosion hiding under some other positive wires that were cobbled together and spliced to the positive terminal behind the breather.

While I was doing this, I installed a quick connection to the terminals to make it easier to plug in the battery tender this winter.



Good luck.

 

[Roadworthy]

If your terminals aren't making good contact your alternator may not charge the battery. Begin by charging the battery fully, then have it load tested. That will confirm the battery is good. Before reinstalling clean the terminals thoroughly as well as the cable ends. Connect cables securely to the battery. If you can move them around they're not secure. Follow the ground lead to the frame. Clean and tighten there. Now start the tractor and with it set to about 1500 rpm check the voltage at the battery. You should see around 13.5 to 14.5 volts. While the tractor is running you can check the voltage at the glow plugs. It should be zero. If it's ten or eleven volts your problem is with the glow plug controller. There should never be voltage there with the key off.

 

[rScotty]

Answers first. Explanations only if you want them.

Yes the system should charge fully at a high idle.... say over 11/1200 rpm. A voltmeter across the battery terminals at 14/1500 RPM will show between 13 and 14 volts DC - but only if the whole system is good. We need to eliminate some things.

Sure, the glow plugs could be the culprits. That's a nice piece of diagnosis. So open the hood and disconnect the wires to the glow plugs..or pull the fuse that activates them. Anything to make sure they are off.

We can figure this out if you want to take a few days to actually know what is happening.

First of all the battery. Is it a wet cell or an AGM. Do you have a "smart charger" & digital voltmeter? Is the digital voltmeter a VOM type that also measures continuity and resistance and can distinguish between AC and DC? We might need those abilitys later....not now.

First, we do the battery. Disconnect both battery leads from the battery.

Now you have a a choice. Taking the battery out and over to the bench is best because you can see the cables better so you can wiggle and inspect them. Look for an internal break in both cables. My Kubota had an internal break half way down the negative cable - I liked to never found it. Also scrape off all the corrosion down to bright metal, and specifically look for corrosion where the neg. bolts to the frame.

Do NOT get the acid salts on your good blue jeans.. If you mess up, use baking soda and water to kill the acid.

OK. Before doing anything, measure the voltage of the discharged battery.
Now hook it up to charger at about 4 to 8 amps overnight. No more amps than that, or you can get overheating and not as good a charge. When you turn the charger on, check across the terminals of the battery with your voltmeter to prove to yourself that the charger is supplying somewhere between 13 and 14 volts to the battery. Charge it overnight. Take it off the charger and let it set for at least an hour. Measure the battery voltage again and make a note of it. If it is less than 12.7 volts, put it back on the charger for all day and then measure again.

If 12.7 or over, the battery is probably good, but we need to let it just sit for 24 hours and measure it again. It should still be above 12.5 volts, preferably 12.6.

If it is a bad battery you will see the voltage slowly fall over the next few days just from sitting there not even hooked up. It will drop to the the 11 volts or less. The loss in voltage is caused by internal current flow from a buildup of sulfates on the plates.

rScotty

 

[Kubotajoe99]

Thank you Roadworthy for the advice. I will do as you suggest and get the battery checked out and clean/tighten cables. I haven't ever checked out the glow plugs so I'll have to find out where they are and which terminals to check. Thanks again.

 

[ns_in_tex]

If your terminals aren't making good contact your alternator may not charge the battery. Begin by charging the battery fully, then have it load tested. That will confirm the battery is good. Before reinstalling clean the terminals thoroughly as well as the cable ends. Connect cables securely to the battery. If you can move them around they're not secure. Follow the ground lead to the frame. Clean and tighten there. Now start the tractor and with it set to about 1500 rpm check the voltage at the battery. You should see around 13.5 to 14.5 volts. While the tractor is running you can check the voltage at the glow plugs. It should be zero. If it's ten or eleven volts your problem is with the glow plug controller. There should never be voltage there with the key off.

Like Roadworthy said, engine 1/2 throttle, should have at least 13 volts at battery. If not, check between battery ground post (actual post, not the clamp) and a metal portion of tractor frame. any volts above 0 equals a poor ground connection somewhere. Check between battery ground post and battery ground clamp. If volts above 0, it is a poor connection at cable clamp. Move around until you get a reading on either side of a specific connection. That is likely the poor connection that needs cleaning or replacing.

This works the same on both + & - wires. When meter probes are on either side of a poor connection, you will get a reading. When all is good, you will get 0 volts.

 

[Kubotajoe99]

Answers first. Explanations only if you want them.

Yes the system should charge fully at a high idle.... say over 11/1200 rpm. A voltmeter across the battery terminals at 14/1500 RPM will show between 13 and 14 volts DC - but only if the whole system is good. We need to eliminate some things.

Sure, the glow plugs could be the culprits. That's a nice piece of diagnosis. So open the hood and disconnect the wires to the glow plugs..or pull the fuse that activates them. Anything to make sure they are off.

We can figure this out if you want to take a few days to actually know what is happening.

First of all the battery. Is it a wet cell or an AGM. Do you have a "smart charger" & digital voltmeter? Is the digital voltmeter a VOM type that also measures continuity and resistance and can distinguish between AC and DC? We might need those abilitys later....not now.

First, we do the battery. Disconnect both battery leads from the battery.

Now you have a a choice. Taking the battery out and over to the bench is best because you can see the cables better so you can wiggle and inspect them. Look for an internal break in both cables. My Kubota had an internal break half way down the negative cable - I liked to never found it. Also scrape off all the corrosion down to bright metal, and specifically look for corrosion where the neg. bolts to the frame.

Do NOT get the acid salts on your good blue jeans.. If you mess up, use baking soda and water to kill the acid.

OK. Before doing anything, measure the voltage of the discharged battery.
Now hook it up to charger at about 4 to 8 amps overnight. No more amps than that, or you can get overheating and not as good a charge. When you turn the charger on, check across the terminals of the battery with your voltmeter to prove to yourself that the charger is supplying somewhere between 13 and 14 volts to the battery. Charge it overnight. Take it off the charger and let it set for at least an hour. Measure the battery voltage again and make a note of it. If it is less than 12.7 volts, put it back on the charger for all day and then measure again.

If 12.7 or over, the battery is probably good, but we need to let it just sit for 24 hours and measure it again. It should still be above 12.5 volts, preferably 12.6.

If it is a bad battery you will see the voltage slowly fall over the next few days just from sitting there not even hooked up. It will drop to the the 11 volts or less. The loss in voltage is caused by internal current flow from a buildup of sulfates on the plates.

rScotty

Thank you for the help! I will figure out how to disconnect the glow plugs and eliminate that from the potential problems.

The battery is a wet cell. My charger is pretty old. I've only got two settings for amperage, 2 amp or 15 amps. Will that work? I do have a digital voltmeter with continuity and resistance measurement and AC and DC settings.

 

[Kubotajoe99]

Like Roadworthy said, engine 1/2 throttle, should have at least 13 volts at battery. If not, check between battery ground post (actual post, not the clamp) and a metal portion of tractor frame. any volts above 0 equals a poor ground connection somewhere. Check between battery ground post and battery ground clamp. If volts above 0, it is a poor connection at cable clamp. Move around until you get a reading on either side of a specific connection. That is likely the poor connection that needs cleaning or replacing.

This works the same on both + & - wires. When meter probes are on either side of a poor connection, you will get a reading. When all is good, you will get 0 volts.

Thanks for the help! I will definitely do as you suggest. I've got a DC mV setting on my volt meter so I should be able to see it if that is the problem.

 

[rScotty]

Thank you for the help! I will figure out how to disconnect the glow plugs and eliminate that from the potential problems.

The battery is a wet cell. My charger is pretty old. I've only got two settings for amperage, 2 amp or 15 amps. Will that work? I do have a digital voltmeter with continuity and resistance measurement and AC and DC settings.

Sure, it will work just fine. I'd probably try it for an hour at 15 amps, and feel of the battery every 20 minutes. If it is warm to the touch, drop back to 2 amps and double all the charging times.
And check across the terminals while it is charging to find out what voltage it is charging at and also look to see if the VOM agrees that what it is measuring is DC. Most VOMs will complain if asked to measure DC when/if they are hooked up to something that seems more like AC to them.

And some old chargers as they age begin to put out a pulsating DC that doesn't do much good for the battery. If it is bad enough, some modern VOMs will see that as AC.

I use a BatteryMinder smart charger and find that it will pay for itself in longer battery life. Plus it's a pretty good diagnostic tool. I use it in trickle charge mode so much I was going to get another one, But the darn things cost so much that I couldn't justify it. So ended up buying one for my buddy instead.
rScotty

 

[jigs_n_fixtures]

I’ve had corrosion inside the insulation on the battery leads which kept the battery from charging fully. Replaced the cables and everything was fine.

Try checking the resistance from one end to the other of both leads with a multimeter. There should be no resistance. If you have any resistance replace the cables.

 

[rScotty]

I’ve had corrosion inside the insulation on the battery leads which kept the battery from charging fully. Replaced the cables and everything was fine.

Try checking the resistance from one end to the other of both leads with a multimeter. There should be no resistance. If you have any resistance replace the cables.

Was that on the TYM? I had never seen corrosion INSIDE the battery cable at any distance past a half inch or so from the battery terminal until I found it happen on my own Kubota. The internal break in the cable wire was halfway along the length. When I split the insulation open to look, it was corrosion sure enough.

The original Kubota wet cell battery lasted from 2008 to the spring of 2021 - but while doing so it cost me two battery cables and ends. Plus creating a tricky problem to find. On voltage-sensitive modern computer controlled tractors it could have created real problems. Luckily this 2008 Kubota is mostly pre-computer.

I replaced the battery with an AGM. That will 100% prevent any battery fume corrosion problem in the future. So we won't be seeing that particular problem again.
rScotty

 

[skipmarcy]

A much cheaper alternative to stop terminal/cable corrosion is to use the old red & green felt washers around your battery posts and SOAK them good with the corrosion inhibitor that comes in spray cans. The impregnated felts usually don't have much inhibitor on them as they come and will only last a short while. I re-spray mine about once a year and they will last the life of the battery and NO corrosion. Wet cell batteries have always leaked either electrolyte or gas around the posts (unless you were lucky and got one with good seals inside). Currently my spray can is the CRC Marine battery spray - I use it on all of my batteries with posts. Much cheaper than a higher priced battery !!

 

[rScotty]

A much cheaper alternative to stop terminal/cable corrosion is to use the old red & green felt washers around your battery posts and SOAK them good with the corrosion inhibitor that comes in spray cans. The impregnated felts usually don't have much inhibitor on them as they come and will only last a short while. I re-spray mine about once a year and they will last the life of the battery and NO corrosion. Wet cell batteries have always leaked either electrolyte or gas around the posts (unless you were lucky and got one with good seals inside). Currently my spray can is the CRC Marine battery spray - I use it on all of my batteries with posts. Much cheaper than a higher priced battery !!

Yes, that is the age-old debate between which way to fix a problem:
1. Should I go with a inexpensive but higher maintenance solution or....
2. Is it better to go for a more expensive and lower maintenance solution.

I think that there is no best answer. But I have noticed that when we are younger we tend to go with with the first solution and when older the second.
rScotty

 

[Kubotajoe99]

I cleaned the battery terminals and cable clamps today. To check the connection from the negative cable clamp to chassis I measured the resistance at several different places on the chassis and when I first touch it, it reads about 1 ohm but if I hold it for a couple of seconds it goes down to 0.2 ohms. Is that low enough for a good connection? On the positive cable I checked the resistance between the positive cable clamp and the positive on the alternator and it also read 0.2 ohms after a couple of seconds.

I charged the battery at 2 amps and in the beginning with the charger connected it read 12.6 volts but over time it got up to about 13.5v. When the charger was disconnected the battery read 12.95v and an hour after charging stopped it read 12.9v, 2 hours after charging it read 12.88v. I'll check it one more time later tonight.

 

[dirttoys]

Hope I didn't miss this above. Probably not the root cause, but, any chance the mech put an alternator on with the wrong size pulley? Alternator too slow, need too much rpm for good charge.

Best,

ed

 

[LittleBill21]

lots of guesses here but, 1 your mechanic is an idiot if he thinks you need to be over 2000 rpms to charge, alternators charge at idle, diesel changes nothing about this

lets be clear your alternator is not charging, its as simple as that. with the engine running check at the positive post at the alternator itself. if not 13+ you have issue with the alternator it self or wiring for the activation, does this tractor have a battery light? does it come on? does it go out?

changing parts just to change parts is a waste of money and parts

 

[rScotty]

I cleaned the battery terminals and cable clamps today. To check the connection from the negative cable clamp to chassis I measured the resistance at several different places on the chassis and when I first touch it, it reads about 1 ohm but if I hold it for a couple of seconds it goes down to 0.2 ohms. Is that low enough for a good connection? On the positive cable I checked the resistance between the positive cable clamp and the positive on the alternator and it also read 0.2 ohms after a couple of seconds.

I charged the battery at 2 amps and in the beginning with the charger connected it read 12.6 volts but over time it got up to about 13.5v. When the charger was disconnected the battery read 12.95v and an hour after charging stopped it read 12.9v, 2 hours after charging it read 12.88v. I'll check it one more time later tonight.

I don't have any idea why your VOM reads an ohm and then eventually drops to 0.2. My guess is that has to do with the meter, not the battery cable. Does it do the same thing when you just touch the two voltmeter leads together?
How about when you measure something metallic - like from one end of your tool box to the other?

Anyway, I'm tempted to call the cables and connectors good, because after all, they did get to 0.2 ohms in a reasonable amountof time, and that is about the right resistance.

Same verdict on the battery test. If that battery still reads over 12.6 volts this time tomorrow I'll call it good.
Do't forget to disconnect the glow plugs. You can look at them in the parts book on Messick's site and see what they look like and how connected.

I just checked that parts catalogue at Messick's online, and your L4610 uses an alternator that has the diode rectifier plate and the voltage regulator built right onto the alternator case so either can be replaced. Not all alternators are made that way, but yours is. And it means that just as LittleBill21 said, if you measure DC voltazge from the insulated connector post on the back of your alternator to the frame of the tractor then whether the battery is hooked up or not you should see between 13 and 14 point something volts at a fast idle.
If you see less voltage, then either the alternator windings are bad, one of the diodes is bad, the voltage regulator is no good, or the grounding brush is worn out.
If you saw over 13 volts on the back of the alternator at a fast idle, now put the the battery into the circuit if it wasn't already, and measure from one post of the battery to the other post. You should see the identical voltage.
If not, then the problem has to be in the wiring between the alternator and battery - probably in the key switch.

Aside:
There are many ways to repair an alternator. They are built to be easily repaired. But that's assuming that you are starting with a stock Kubota alternator, and it sounds like your mechanic replaced it with something else.

A stock Kubota alternator brand new costs about $320 retail, and comes with all the right brand new parts. It mounts with two bolts and one wire. Depending on what you measure for voltage, that might be where you end up.
Good Luck,
rScotty

 

[Gord Baker]

Both ends of the Negative (Ground) cable are equally important. REMOVE both ends and provide a bright metal to metal contact. Grease them if you wish After tightening.
Visually inspect ALL wiring - lighting included. You may have a severe short circuit to kill the battery that quickly.