L2350 wiring -positive battery cable and the spare red wire

L2350 Excitor

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Kubota L2350 DT
Jul 9, 2020
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My positive battery cable post harness broke - it had an extra small red wired on it but I’ve not been able to back and figure out where that wire went or was supposed to go. I could not find a replacement so I just replaced with a single harness that just has the one large cable wire; Everything seems to work - the tractor overhears after a coup,e hours or hard bush hogging then won’t start for an hour, then starts right up once cool.
So my questions are: what is that extra wire and is it just incorporated into the main cable?
2. Is there a switch that prevents the tractor from starting til it cools to certain
Temperature?
Thank you!
 

Jim L.

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Jun 18, 2014
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the tractor overhears after a coup,e hours or hard bush hogging then won’t start for an hour, then starts right up once cool.

Most operators don't realize that the cumulative effects of running hot can be just as damaging as pegging the meter to the red end. Running hot causes the block, head, and head gasket to expand and contract at different positions. This relative movement stresses the gasket and can lead to gasket failure and head failure.

The solution is to keep the radiator clean of dirt, chaff, and seeds. There are air wands and water wands to safely do this without bending radiator fins. It sounds that your machine is at the point where the radiator needs to be removed and be cleaned where you can look through the fins to get it clear.

When bush-hogging or hard mowing, put the tractor in low gear to slow the feed of material into the blades.
 
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NHSleddog

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the tractor overhears after a coup,e hours or hard bush hogging then won’t start for an hour, then starts right up once cool.

Most operators don't realize that the cumulative effects of running hot can be just as damaging as pegging the meter to the red end. Running hot causes the block, head, and head gasket to expand and contract at different positions. This relative movement stresses the gasket and can lead to gasket failure and head failure.

The solution is to keep the radiator clean of dirt, chaff, and seeds. There are air wands and water wands to safely do this without bending radiator fins. It sounds that your machine is at the point where the radiator needs to be removed and be cleaned where you can look through the fins to get it clear.

When bush-hogging or hard mowing, put the tractor in low gear to slow the feed of material into the blades.
One other suggestion, blow out the radiator from behind with air first. I use my makita blower with a shop vac hose on it to get in behind it. This way you are removing a ton of debris, dry, and in the direction it came, not forcing it further in.

Never use water from the front. Using water from the front will create a little more concrete every time you pack a little more in there. It will look clean, but over time it will be packed so hard it will be tough to get clean. It will also run a little hotter every time.

Check the part in the parts manual.
 
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L2350 Excitor

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Kubota L2350 DT
Jul 9, 2020
10
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1
USA
the tractor overhears after a coup,e hours or hard bush hogging then won’t start for an hour, then starts right up once cool.

Most operators don't realize that the cumulative effects of running hot can be just as damaging as pegging the meter to the red end. Running hot causes the block, head, and head gasket to expand and contract at different positions. This relative movement stresses the gasket and can lead to gasket failure and head failure.

The solution is to keep the radiator clean of dirt, chaff, and seeds. There are air wands and water wands to safely do this without bending radiator fins. It sounds that your machine is at the point where the radiator needs to be removed and be cleaned where you can look through the fins to get it clear.

When bush-hogging or hard mowing, put the tractor in low gear to slow the feed of material into the blades.

I actually think most do understand that the radiator and whole tractor get hot. The whistle goes I’ve over done it - and frequently do. That said I want to know why the starter just clicks until it cools about 90 minutes. Is the starter hit and that affects the brushes? Is there a auto block when it’s a certain temp?
I want to know if a wire that excites the alternator or something straight off the battery is missing and that causes my battery to not charge....then again as soon as it’s cool it starts right up. I can’t figure it out!
 

Jim L.

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I get it that you're focused on the electrical part. Unfortunately I don't have an L2350 wiring diagram. Maybe Dave will come along to help.

Sometimes there is a conductor going straight to the starter or alternator. I just don't know how the L2350 is wired. I also don't know what the replacement part got connected between.

To my knowledge there is not an inhibit for high temperature in the electrical circuit. My guess is that it is just as likely that a fuel line is getting too hot, versus an overheated starter or solenoid.

The main thing that I am trying to convey is that continuing to run hot will mean a new $1000 head and $100 gasket, not counting labor cost.

Besides cleaning the radiator, check the belt and fan, and that the coolant is sufficient and is not blocked.
 

Dave_eng

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This is a quick response to your posts.

You appear to have abandoned the second most important wire in the wiring harness. One that connects the regulator to the battery, one that lets the regulator see the state of charge of the battery.

Likely your battery is dying a slow death and has to sit in order to recover enough to start the engine again. Soon, I predict it will no longer be able to start the engine being to undercharged.

The only "inhibit" on your tractor is a dying battery.

I have attached the wiring diagram.

Dave
 

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GeoHorn

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This is a quick response to your posts.

You appear to have abandoned the second most important wire in the wiring harness. One that connects the regulator to the battery, one that lets the regulator see the state of charge of the battery.

Likely your battery is dying a slow death and has to sit in order to recover enough to start the engine again. Soon, I predict it will no longer be able to start the engine being to undercharged.

The only "inhibit" on your tractor is a dying battery.

I have attached the wiring diagram.

Dave
The battery is not depicted in that diagram, but the regulator is energized whenever the alternator is powered thru the ign switch, so the point you are attempting to make is not valid if I‘m reading it correctly Dave.

Excitor: Many battery cables have an additional short lead so that accessories may be “hot wired” to the positive battery post. Not all tractors use it. If yours doesn’t need it...no harm is done in replacing it with one that doesn’t have it.
 

BruceP

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My positive battery cable post harness broke - it had an extra small red wired on it but I’ve not been able to back and figure out where that wire went or was supposed to go. I could not find a replacement so I just replaced with a single harness that just has the one large cable wire;
I cannot speak for your specific tractor but I have worked on 100s of electrical systems.

*) The BIG red wire goes directly to the starter. (no fuse) and is ONLY used for starting the engine.
*) The smaller red wire usually has a fuse and feeds the rest of the electrical system. (lights, charging the battery...etc)
 

Dave_eng

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The battery is not depicted in that diagram, but the regulator is energized whenever the alternator is powered thru the ign switch, so the point you are attempting to make is not valid if I‘m reading it correctly Dave.

Excitor: Many battery cables have an additional short lead so that accessories may be “hot wired” to the positive battery post. Not all tractors use it. If yours doesn’t need it...no harm is done in replacing it with one that doesn’t have it.
The battery IS depicted in the wiring diagram if you look closely. My original comments are correct.

I have taken a section of the wiring diagram and drew a line to the battery.

Forum L2350 battery.jpg


Dave
 

GeoHorn

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Thanks, Dave. (That is the most diminutive depiction of a battery I’ve ever seen.)
The comments I made earlier still seem valid... the alternator and regulator are both powered by the same BIG red positive battery lead.
 

Dave_eng

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Thanks, Dave. (That is the most diminutive depiction of a battery I’ve ever seen.)
The comments I made earlier still seem valid... the alternator and regulator are both powered by the same BIG red positive battery lead.
I agree when I first looked it was like I was back in a physics class.... not clear.

My point is that with the alternator having an external regulator, there is nothing to turn on the alternator absent a connection to the battery which is what the owner has done by omitting the red wire connection at the battery,

The battery, regulator and alternator + the tractor's wiring all depend upon the not connected red wire. At least the fusible link will never blow :)

Dave
 

GeoHorn

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Dave, that’s not the way I read it. Where do you see a small, separate connection to the battery for the regulator and other items?
 

Jim L.

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Gents

Unfortunately the wiring diagram does not show conductor gauges.

I have to wonder if the replaced battery lug set was not the original cable set.

The wiring diagram shows the feed to the alternator field coil as passing through a fuse.

Maybe another owner of the same model can describe their setup.

I would also think that the OP could electrically check to see if his alternator is charging the battery if given sufficient instructions.
 

Dave_eng

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Dave, that’s not the way I read it. Where do you see a small, separate connection to the battery for the regulator and other items?
You must recognize that the wiring diagrams are not exact representations of where wires actually are both on the tractor and within the harness. They are a schematic representation (aka a sketch) to help explain and demonstrate what connects to what.

The connecting of the two wires is shown taking place at the opposite end of the main battery cable to what the owner sees but, from a design and maintenance point of view those two circuits are connected and further nothing gets into the tractor electrical system without passing through the fusible link save and except the current between the battery and starter.

When you move to more involved wiring say in an industrial setting, you will have both a ladder wiring diagram and a schematic diagram.

Neither is intended for production of the harness but rather for "in the field," maintenance and troubleshooting.

The wiring diagram Kubota production engineers would hand to the production floor would look nothing like what is in the WSM.

Forum L2350 battery 2.jpg


This is another wiring diagram from the same manual. It looks different but in reality the wire interconnections are the same.

Forum L2350 battery 3.jpg


Dave
 
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North Idaho Wolfman

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There will not be any FACTORY small wire to the battery, the only battery small wire connectors are on the Starter lug where they will attach to the large cable via a fuse or fusible link.

Most likely the wire is some "fix" or "add on" like lights.

OK now onto the overheating issue, there is nothing in the mechanical or electrical system that stop the tractor from cranking when hot.
If you're getting it that hot it just a matter of time before it just won't start again!
There is no reason for the tractor to be overheating no matter what your doing with it, so basically you have a problem that your choosing to ignore, and it will bite you eventually.
 

L2350 Excitor

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Kubota L2350 DT
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You guys are great. This is my original cable when I bought the L2350.
You are all correct the main cable goes to the starter, but a second red wire is screwed to that cable, that goes to a coupling with a blue wire 1 inch loop- then proceeds on as a red wire into the rest of the electrical system.

Sounds like consensus is the wire off the original cable doesn’t matter.

The overheating is hard - L2350s have a bolted fan shroud behind a bolted screen under a bolted top hood - accessible through screwed side panels. Leave blower compressed air - all limited access through the back of the fan dynamo. I spray air anyway I can but with limited effect. It would overheat less if stopped every hour. You’ve shamed me into that now so ok.

Last thing to mention - I have headlights that work but 2 of the 6 lines feeding them juice are cut. - orange and black lines. Can I tell from the wiring diagram what the orange and black lines are supposed to power?
 

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Jim L.

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Last thing to mention - I have headlights that work but 2 of the 6 lines feeding them juice are cut. - orange and black lines. Can I tell from the wiring diagram what the orange and black lines are supposed to power?

From the headlight switch orange and brown conductors power the left, right; high and low headlamps.

Black conductors are for chassis, negative battery.
 
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Dave_eng

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You guys are great. This is my original cable when I bought the L2350.
You are all correct the main cable goes to the starter, but a second red wire is screwed to that cable, that goes to a coupling with a blue wire 1 inch loop- then proceeds on as a red wire into the rest of the electrical system.

Sounds like consensus is the wire off the original cable doesn’t matter.

The overheating is hard - L2350s have a bolted fan shroud behind a bolted screen under a bolted top hood - accessible through screwed side panels. Leave blower compressed air - all limited access through the back of the fan dynamo. I spray air anyway I can but with limited effect. It would overheat less if stopped every hour. You’ve shamed me into that now so ok.

Last thing to mention - I have headlights that work but 2 of the 6 lines feeding them juice are cut. - orange and black lines. Can I tell from the wiring diagram what the orange and black lines are supposed to power?
Does the wire loop you mention look like this?
forum L2350 fusible.jpg


If it does then this is the fusible link aka fuse that feeds the entire tractor. It is surprising if your link is not in the system that the tractor starts and runs.

Dave
 

Jim L.

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Jun 18, 2014
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You are all correct the main cable goes to the starter, but a second red wire is screwed to that cable, that goes to a coupling with a blue wire 1 inch loop- then proceeds on as a red wire into the rest of the electrical system.

The blue wire loop is the fusible link which protects the wiring.

The side of the fusible link which does not go into the electrical harness - how is that connected to the starter where the big wire from the battery is attached?
 

L2350 Excitor

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Kubota L2350 DT
Jul 9, 2020
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The side of the fusible link which does not go into the electrical harness - how is that connected

The link looks exactly like the picture but blue wire - it is screwed to the same post as the starter.