Kubota L4610 electrical problem (need help please)

[iateyourcat]

My L3301 would not start often, even when it had just been running. I could leave it alone and it would eventually start. I thought I had battery, alternator or safety switch issues. It was in the shop for 3 months and came out the same way. After eliminating battery, switch and safety issues myself and after a ton of reading I found this: Amazon.com: HD Switch Starter Relay Kit AM107421 Replaces John Deere AM107421 is Compatible with John Deere : Automotive There simply isn't always enough juice getting to the starter.

This explains the issue much better than I can:

I bought mine July 3rd 2019 and haven't had a single battery or starting issue since.

 

[sunandsand]

Quick no-tools alternator check: Start engine, let idle, turn on headlights. Have someone look at them, and rev the engine. If they get brighter, the alternator is charging. If they don't, it isn't. While an alternator will charge at idle, faster is better.

Battery - charge at 1/10 the amp-hour rating of the battery. You can use more, but the battery can get hot which will warp the plates or I have even seen batteries burst! The battery MAY be at the end of the service life anyway, it is at least three years old, we don't know how long it sat before you got it, and batteries don't like vibration much - we all know how silky-smooth tractors are ;-)

(How cold does it get where you are? Batteries in cold climates don't last as long as in warmer areas.)

Find a service station with a load tester (first find a service station!) or better, an auto electric repair place, and do a load test on the battery. Don't be too unhappy if you need a new one because that may be your problem.

Corrosion on battery wires - I have a Honda (beater) which had corrosion on the positive wire almost eight inches down inside the plastic jacket. "Hmmm, that don't look right, how come it is all bulgy?" Honda wanted $122 for the part, eBay had the same part for $23 and it arrived in a Genuine Honda Parts bag, red letters and all. (That's a hint for shopping!)

A diesel will run with no electrical power at all other than glow plugs and starter, so I think your problem could be:

Bad battery

Corrosion on battery terminals or wires

Some drain somewhere - chafed wire, glow plugs not turning off (check your ignition switch by referring to the schematic and using an ohmmeter, it may have broken down internally).

I think replacing the alternator is an exercise in spending money uselessly - the problem is somewhere else.

There really should be no draw on the battery once the engine is running unless you have anti-aircraft spotlights and/or a 60,000 watt sound system on the tractor.

Yes, electrical problems are a PITA to find sometimes but always check the simple things first, don't get involved with guesses which will only cost you money and not fix the problem.


Best Regards,

Mike/Florida

 

[ljjhouser]

Just some general information that may or may not help. Many years ago, generators always had an external voltage regulator. Then came alternators (yes, they should charge just above idle, generators needed high rpm). Alternators now have built in solid state regulators.
To the point. I am wondering if you have an excess load somewhere. Even a high resistance short. That could place a load on the alternator and burn out the internal regulator.

At one point in my life, I was part owner in several aircraft. We owned a Beech Bonanza. Someone flew it from KC to PA. When he was ready to take off again, the runup showed a problem with the alternator. The FBO (Fixed Base Operator) said the alternator was bad and replaced it. $2000. Things went well for 2 months. Then someone flew it to Denver Stapleton. Again, bad alternator. $2000. This happened a third time. $2000. When it came back to KC, I put it in the local FBO to find the problem. They said noting is wrong with it.

The next week, I was in the hangar working on the wingtip light of that aircraft. I decided to check all external lights. I found that the wing landing lights were 150 watts each. I thought that was a lot - 300 watts at 12v is pretty close to 26 amps - I went into the plane and added up all the radio amperage. It was too much. After checking the manual, the landing lights were supposed to be 40 watt high intensity. Changed the landing lights, problem ended. When landing at night, turning on the landing lights on approach fried the internal regulator. Couldn't handle the load.

You may need the see if there is a short or spike somewhere in the wiring or a part causing an overcurrent situation.
This represents the hardest to find situation.

Also wonder how old is the battery. Might replace it anyway if older. That is if the alternator is charging correctly.
You tractor runs on the alternator current. Only on the battery when starting and if the alternator doesn't provide enough current, then battery discharges.

 

[Fxfymn413]

Lots of worthy advice here and intermittent electric issues will get you talking to yourself pretty quickly. I'd stop and look at the overall problem as the first troubleshooting step.

Given the age of the tractor I would suspect some corrosion as the most likely suspect and since the problem appears to cure when the alternator was replaced I'd check whatever wires the mechanic touched during the replacement. (He/she should disconnect the battery so don't forget that.) If nothing else you can disconnect the main feed wire from the alternator to the battery and put a temporary jumper in its place to see if the problem disappears.

Did you ensure the belt is tight and in good condition? A really far out stretch is a bad shimmy dampener that is slipping.

 

[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 tonig ht.

Thanks to everyone for all of the helpful advice! It's now been 24 hours since taking the battery off the charger and leaving it on the bench. It now reads 12.78v. While it was out of the tractor I completely removed the negative battery cable and checked the resistance from the clamp to the connector. It seems fine and measured 0.1 ohm. My volt meter actually reads 0.1 ohm most of the time when I contact the leads together, so I feel like the negative battery cable is good. I sanded down the connecting area and the connector to shiny metal before reinstalling.
Next I would like to eliminate the possibility that a faulty glow plug circuit isn't turning off after starting the tractor, so I started looking for the glow plug that has the positive connection, but I don't know exactly what it looks like or where it is. I found what I believe are 4 glow plugs in a single row and one glow plug not in the same row as the other 4, and that confused me. On the 4 in single row there is a single metal strip connecting them together. The confusing thing is that I expected to see all the glow plugs in a single row with positive connected at one end and negative connected to the last glow plug in the row. Something like this:

+ terminal connected to GP1 -> GP2 -> GP3 -> GP4 -> GP5 - terminal connected

What I think I'm seeing is like this:

- terminal connected to GP2 -> GP3 -> GP4 -> GP5
+ terminal connected to GP1

The one not in the row with the others, that has what I think may be the + terminal, has a spade type connector, so easy to disconnect. This is located on the right side of the engine under the fuel cap area.

Can anyone confirm that this is the positive terminal for the glow plugs? If so, my plan is to reinstall the battery, turn on the key but not start it, check the voltage at the + terminal of GP1 to confirm voltage, then check voltage at + terminal on the alternator and note it, then start the tractor then check the voltage again at the + terminal of GP1 to confirm that its 0v, then check the voltage again at the + terminal of the alternator again. I assume it should be over 13 volts at fast idle.

 

[grsthegreat]

Quick no-tools alternator check: Start engine, let idle, turn on headlights. Have someone look at them, and rev the engine. If they get brighter, the alternator is charging. If they don't, it isn't. While an alternator will charge at idle, faster is better.

Battery - charge at 1/10 the amp-hour rating of the battery. You can use more, but the battery can get hot which will warp the plates or I have even seen batteries burst! The battery MAY be at the end of the service life anyway, it is at least three years old, we don't know how long it sat before you got it, and batteries don't like vibration much - we all know how silky-smooth tractors are ;-)

(How cold does it get where you are? Batteries in cold climates don't last as long as in warmer areas.)

Find a service station with a load tester (first find a service station!) or better, an auto electric repair place, and do a load test on the battery. Don't be too unhappy if you need a new one because that may be your problem.

Corrosion on battery wires - I have a Honda (beater) which had corrosion on the positive wire almost eight inches down inside the plastic jacket. "Hmmm, that don't look right, how come it is all bulgy?" Honda wanted $122 for the part, eBay had the same part for $23 and it arrived in a Genuine Honda Parts bag, red letters and all. (That's a hint for shopping!)

A diesel will run with no electrical power at all other than glow plugs and starter, so I think your problem could be:

Bad battery

Corrosion on battery terminals or wires

Some drain somewhere - chafed wire, glow plugs not turning off (check your ignition switch by referring to the schematic and using an ohmmeter, it may have broken down internally).

I think replacing the alternator is an exercise in spending money uselessly - the problem is somewhere else.

There really should be no draw on the battery once the engine is running unless you have anti-aircraft spotlights and/or a 60,000 watt sound system on the tractor.

Yes, electrical problems are a PITA to find sometimes but always check the simple things first, don't get involved with guesses which will only cost you money and not fix the problem.


Best Regards,

Mike/Florida

agree, except for the part of batteries in colder climate not lasting as long as in hot climates. heat kills a battery . super severe cold probibly doesnt help much either, but the chemical reactions within a battery speed up in hot weather and slow down in sever cold. thats why a battery will get sluggish. but ive had batteries fail in a few years when i lived in calif, but i get 5-7 in north idaho.

 

[Williy]

The simplest way to test to see if alternator is
functioning clamp your volt meter to the battery
plus to plus and minus to minus then start your
engine if the needle or meter don't show an increase
your alternator is not working. Check an auto parts
store for a cheap replacement!

the way the voltage drops its possible to have a bad cell
in the battery

willy

 

[sunandsand]

I want to clarify my earlier message slightly - Dear Bride was telling me to hurry up and lets GO!

Once a diesel is started and running, there is no further need for electricity to run the engine. The starting sequence is power to the glow plugs, crank engine, when it is running, stop cranking and disconnect power to the glow plugs.

The only reason we even have an electrical system on a diesel tractor is to get the darn thing started (and hey, since we already HAVE an electrical system, we can run lights and a radio, and maybe even a Jacuzzi, if desired).

What I am reading is that the battery isn't charging back up and the second or third start is difficult or it won't start at all.

My suspicion is that the battery is simply shot. That can be checked with a load tester. An end-of-life battery won't take or keep a charge. It may show 13.5 volts on a voltmeter after it has been charged for a while, but the first time you crank the engine, it won't recover, even if the alternator is working perfectly.

The next thing I'd look at is this - is the alternator charging? Do the headlight trick on that one. If the headlights get brighter, the alternator works. If they stay dim, it doesn't. Understand that you could possibly have a bad alternator AND an end-of life battery. The lack of power from the alternator might have pushed the already feeble battery off the cliff.

You are quite correct in looking for voltage on the glow plugs with the engine running - there shouldn't be any. If there is, there could be an internal defect in the ignition switch which lets power continue to go to the glow plugs even though the key has been released from "start" to the "run" position.

You can find this without a schematic if you find the +12 volt wire IN to the switch and the glow plug wire OUT of the switch. Disconnect the battery first, then turn the switch to "start", it should show zero ohms between the two terminals (it will because you know you have power to the glow plugs, the engine woun't start without that), return to "run", the meter should show "open" between the two terminals. If it shows zero ohms or close to it in the "run" position, you've found the problem. The schematic does make it easier, it will show what terminals are connected to what wires internally in the various switch positions.

Your voltmeter has an internal battery. These don't last forever, and when they get old, it becomes difficult to measure low resistances (which may be why you are getting readings of .2 ohms and similar). Be sure you can "zero" the meter by touching the probes together (ohms scale) and turning the knob so the meter reads zero. If it won't zero, the internal battery is shot - it is usually a AA battery or two, or a 9 volt battery.

Final caution with the meter - don't accidentally try to measure any voltages with the meter selector set to ohms. That will cook the meter. Harbor freight sells these things for $5 each, I have four of five of them laying around so if I run over one with the tractor or one grows legs and walks away, I have a spare.

Don't over-analyze this, it is really seldom that truly exotic problems arise. Most electrical problems are simple, something is loose, cooked, corroded or just plain shot.

(I'm a member of the Bulova Accutron watch group - that's the old model with the tuning fork. There was a RAGING, FURIOUS discussion about the definite effects of metal fatigue on the tuning fork and how much that would affect accuracy, which way, and how it could be compensated for. It got VERY esoteric, and I kept my mouth shut and my fingers off the keyboard. Turns out the battery in the guy's watch was dying - a new battery fixed everything.)

Just be happy this is a tractor with a simple electrical system. Buddy of mine has a Suzuki Burgmann (650cc scooter), I have the schematic and there are more wires, switches and sensors in it than in many cars - it even has a USB-II plug! If he asks, I dunno nuttin about electrics, I kin jest barely work a light switch . . .

Best Regards,

Mike/Florida

 

[LittleBill21]

Be aware a ohm test does not remotely confirm a good cable. I am not going to get into why, but a voltage drop test should be performed on high current cables. this proves good cables.

I am not sure why your going down the glow plug path. just check the alternator voltage, and work back to the battery.

you don't have a bad battery, bad battery's either get hot, or sulfate, both of which still will cause the voltage to rise, or the amperage to increase.

please keep it simple. you can do most of these tests in a couple minutes.

 

[sunandsand]

"agree, except for the part of batteries in colder climate not lasting as long as in hot climates. heat kills a battery . super severe cold probibly doesnt help much either, but the chemical reactions within a battery speed up in hot weather and slow down in sever cold. thats why a battery will get sluggish. but ive had batteries fail in a few years when i lived in calif, but i get 5-7 in north idaho."

Quite correct, the battery's chemical reactions speed up in hot climates and slow down in cold climates.

They don't like to be really, really hot, and they don't like to be really really cold either. (I left this out earlier because Dear Bride was pushing to get me out the door.)

All we can confidently say about battery life is "YMMV". Some batteries will last two years if you take care of them, others will last 24 months if ignored.

Best Regards,

Mike/Florida

 

[JWR]

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

Yeah, verily. I agree . The first thing to change is your "mechanic." Certainly getting good clean connections and conduction at the cables and frame, etc. are good advice but you must have something else going on. Replacing the alternator twice as you described is absurd.

 

[Kubotajoe99]

Thanks to everyone for all of the helpful advice! It's now been 24 hours since taking the battery off the charger and leaving it on the bench. It now reads 12.78v. While it was out of the tractor I completely removed the negative battery cable and checked the resistance from the clamp to the connector. It seems fine and measured 0.1 ohm. My volt meter actually reads 0.1 ohm most of the time when I contact the leads together, so I feel like the negative battery cable is good. I sanded down the connecting area and the connector to shiny metal before reinstalling.
Next I would like to eliminate the possibility that a faulty glow plug circuit isn't turning off after starting the tractor, so I started looking for the glow plug that has the positive connection, but I don't know exactly what it looks like or where it is. I found what I believe are 4 glow plugs in a single row and one glow plug not in the same row as the other 4, and that confused me. On the 4 in single row there is a single metal strip connecting them together. The confusing thing is that I expected to see all the glow plugs in a single row with positive connected at one end and negative connected to the last glow plug in the row. Something like this:

+ terminal connected to GP1 -> GP2 -> GP3 -> GP4 -> GP5 - terminal connected

What I think I'm seeing is like this:

- terminal connected to GP2 -> GP3 -> GP4 -> GP5
+ terminal connected to GP1

The one not in the row with the others, that has what I think may be the + terminal, has a spade type connector, so easy to disconnect. This is located on the right side of the engine under the fuel cap area.

Can anyone confirm that this is the positive terminal for the glow plugs? If so, my plan is to reinstall the battery, turn on the key but not start it, check the voltage at the + terminal of GP1 to confirm voltage, then check voltage at + terminal on the alternator and note it, then start the tractor then check the voltage again at the + terminal of GP1 to confirm that its 0v, then check the voltage again at the + terminal of the alternator again. I assume it should be over 13 volts at fast idle.

Today I took one last bench voltage reading before re-installing the battery. Prior to installation it read 12.74v. After installing with the engine off, I took a voltage reading at the battery terminals and it was 12.63 and then took a voltage reading at the alternator positive terminal and it also was 12.63v. Then when I started the tractor and let it idle at about 1400 rpm for a couple of minutes I took both readings again. At the battery terminals it was 12.46v and at the alternator positive terminal it was 12.90v. This surprised me so I redid all of the measurements again and got similar readings: battery terminals 12.48v and alternator positive terminal 12.85v with engine running. So I'm losing about 0.4 to 0.5v between the battery and the alternator power terminal when the engine is running. Does that sound right? By the way it doesn't appear to change the readings significantly if I disconnect the glow plug power wire or have it on. So two questions: Should there be voltage at the power terminal on the alternator with the key off? and, Should there be any voltage drop between the alternator power terminal and the battery terminals when it is idling at 1400 rpm?

 

[LittleBill21]

how many wires are on this alternator, if you disconnect the battery, what is the voltage on the alternator?

@rScotty do you have a wiring diagram?

 

[ruffdog]

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.

Most of the time the tractor is run at idle (1400 rpm)or within 100 rpm of idle? That ain't right......

 

[sunandsand]

"when it is idling at 14000 rpm"

Amusing typo, gotta be a Pratt and Whitney PT-6 turboprop. 1,500+ hp would plow that field in a heartbeat!


There's a fairly easy way to check if there is a drain somewhere (such as the glow plugs not turning off - are they on a relay? It might be stuck on).

Start the engine, disconnect the + terminal on the battery, and put a test light between the battery terminal and the wire you disconnected. If it lights up, something, somewhere is drawing current. If it doesn't light, there is no load draining the battery (on a diesel, no electricity is needed beyond startup).

If there is no load/no light, next step is to load test the battery, and expect it to be bad - won't hold a charge.

Best Regards,

Mike/Florida

 

[Kubotajoe99]

Today I took one last bench voltage reading before re-installing the battery. Prior to installation it read 12.74v. After installing with the engine off, I took a voltage reading at the battery terminals and it was 12.63 and then took a voltage reading at the alternator positive terminal and it also was 12.63v. Then when I started the tractor and let it idle at about 1400 rpm for a couple of minutes I took both readings again. At the battery terminals it was 12.46v and at the alternator positive terminal it was 12.90v. This surprised me so I redid all of the measurements again and got similar readings: battery terminals 12.48v and alternator positive terminal 12.85v with engine running. So I'm losing about 0.4 to 0.5v between the battery and the alternator power terminal when the engine is running. Does that sound right? By the way it doesn't appear to change the readings significantly if I disconnect the glow plug power wire or have it on. So two questions: Should there be voltage at the power terminal on the alternator with the key off? and, Should there be any voltage drop between the alternator power terminal and the battery terminals when it is idling at 14000 rpm?

LittleBilly21 asked me what the voltage was at the alternator with the battery disconnected. My immediate thought was 0v of course, but I thought I'd check just in case, so I disconnected the battery and measured the voltage at the alternator and sure enough it was 0v. So I reconnected the battery cables and checked the voltage of the battery with the engine off and it was 12.60v and checked the voltage of the alternator (with engine off) and it also was 12.60v. But this time when I started the engine and check both of them, the voltage at the alternator was 14.44v and at the battery it was 14.14v. That is certainly enough voltage to charge the battery now, but is it too high? I'm not sure why the alternator suddenly went from 12.85v output before to 14.44v now. The only thing that I did between those readings, which were about an hour apart, was disconnect the battery and re-connect it.

 

[LittleBill21]

yea, I meant check it running, but whatever.


14.44 is correct. you have/had a issue with the battery cable going to the alternator, i would look it over, clean it up, sand, scrape the connectors, and re attach and check voltages again.

again your battery is fine, as much as everyone else keeps saying its bad. if a battery disconnected holds over 12.5 for 24 hours, its in good shape.


let me make another comment, the alternator cable may not go directly to the battery, it may go to the starter, and the battery may go to the starter as well, you need to trace this or confirm it via wiring diagram. with your pulling and pushing you prolly moved the cable to work. I would look at the positive side of the starter and make sure that is not where your issue is as well

 

[sunandsand]

Agree, the alternator is good. 14.4 volts = happy alternator.

Follow the wires from the alternator back to the battery, it is beginning to sound like that's your problem.

Each cell of a lead-acid wet battery is 2.2 volts, so a six volt battery is actually 6.6 volts, and a 12 volt battery is actually 13.2 volts. You have to have a higher voltage than that so the battery will charge. 14.4 is right on the money.

(Have you tested the battery with a hydrometer yet? You could have a single bad cell.)


Loose wire, abraded wire, corroded wire, go over it like it is your worst enemy and you're going to take it to court ;-)

Best Regards,

Mike/Florida

 

[ns_in_tex]

Agree, the alternator is good. 14.4 volts = happy alternator.

Follow the wires from the alternator back to the battery, it is beginning to sound like that's your problem.

Each cell of a lead-acid wet battery is 2.2 volts, so a six volt battery is actually 6.6 volts, and a 12 volt battery is actually 13.2 volts. You have to have a higher voltage than that so the battery will charge. 14.4 is right on the money.

(Have you tested the battery with a hydrometer yet? You could have a single bad cell.)


Loose wire, abraded wire, corroded wire, go over it like it is your worst enemy and you're going to take it to court ;-)

Best Regards,

Mike/Florida

I remember one time in past, my L4610 alternator quit charging. We took it to the shop and they told me it was OK. Put it back on, then found the wire broken. Can't remember exactly where, but think it may have been only 24" away from the alternator. I think it may have been inside a protective shield.

 

[jimer1972]

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.

I don't have a Kubota but if you don't need the rpm then I would change the pulley to a smaller diameter size.
You might also do a parasitic test of you have a fuse box. * Disconnect the + cable then put a meter between the cable and battery with ampere setting on. Observe the amps. If there is a draw then start pulling fuses one at a time and see which one (fuse) brings your amp draw back to zero. This will tell you if you have a short somewhere in the system.
If you are still confused Google [parasitic draw].
Good luck