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