B2400 starting problem finally solved

[Gator6x4]

Those things add some voltage drop headed for the trigger of the solenoid but they do not affect the voltage or current on the heavy cable side. Right?

The problem is that insufficient voltage is reaching the solenoid to provide it with the current to close the heavy duty contacts in the starter that are powered by the heavy duty battery cable. The small wire coming from the ignition switch to the solenoid is the wire experiencing the voltage drop. The relay when wired according to the diagram provided uses the voltage, regardless of volts, 9-10-11 etc to collapse the relay sending battery level voltage to the solenoid which provides it with the omp needing to force the two large contacts in the starter together which in turn causes battery voltage provided by the large cable to the starter which in turn causes it to rotate or spin.

how a starter solenoid works - Google Search

 

[JWR]

Sure. Makes sense. I misinterpreted your diagram in the earlier post. Wire numbered 87 goes as it says "to the solenoid" but means NOT to the heavy cable connection into the solenoid, rather to the trigger (primary) side of the solenoid. Duh, of course. ... in that use of an extra relay I see why that would work to trigger the solenoid, not to provide a heavier starting current path from the battery. Among the various posts I think there was confusion about that.

I'm still puzzled as to what we hear clicking when the problem is present. I recall that being a single click (not the kind of repeated click we hear when a car battery is just low...)

 

[JWR]

CADplans, I like the simplicity of just using larger starter cable if that is an answer. Certainly the relay idea just provides more starting current and maybe that is the core issue. I gotta get out from behind this pc and out to the garage and poke into my BX2200... One thing that immediately comes to mind is: Are the starter cables all that small ? The engine and the starter motor are rather small on a BX2200. Wonder also ... Why do we never ever hear of such a problem with automotive cases?

For whatever reason the forum has turned off my ability to edit this post. Maybe that goes off after a day or two? Anyway...

CORRECTION: This post #76 above was erroneous on my part. The relays people are using are NOT to provide more starting current but rather to get an honest 12v to the primary side of the solenoid.


As Gator6x4 has detailed very patiently for us, the root of the problem is degraded voltage at the primary side of the solenoid due to voltage drops in the serial chain of various safety interlocks. That also explains why the problem is occasional and not always present -- because the voltage to trigger the solenoid is marginal and sometimes makes it and sometimes does not. Thus any means to put a full battery voltage to the solenoid amounts to a permanent fix. Now I can agree with the title of the thread -- "starting problem finally solved."

 

[JWR]

So...I finally visited the southern MD authority on all things starter/motor slash electric: Sr. Techn there told me: 1) This click and fail to trigger the solenoid is VERY common. 2) JD has a kit for sale specifically aimed at correcting the issue (as some have alluded to on this thread but I did not see that JD had issued it as a kit intended for this problem.) 3) He agrees that the issue arises because of marginal voltage getting to the primary side of the solenoid. 4) Commented that because the whole issue is marginal (not a big go-no go thing) many different actions affect it. He often takes off the starter, cleans all the contacts and puts it in top shape and that usually makes the problem go away. Says trying to locate which of the several safety interlocks is causing the most of the voltage drop is 'not worth the labor to chase it.' Almost any small 12v relay installed in the primary side for the solenoid cures the problem. He has installed several kinds. AND it is certainly not just Kubota. He has seen essentially every brand of small tractor with the same disease.

 

[Alien]

As a mechanic I can tell you this problem has been around for years on older motor vehicles. A relay was the quickest most economical solution due to ageing wiring and loss of current through a resistance build up over time. Only other option was to run new ignition/starting circuit wiring which takes more time. Tractors are no different.

 

[JWR]

:thumbsup: Yeah verily Mr Alien from down under ! We do need a "Like" button or something on this forum instead of having to do another post just to concur. I suppose you are going into winter soon down there. Hope you don't see too much Chinese virus.

 

[Alien]

Yes, JWR. Still pretty warm here considering it is Autumn. Luckily I live in the 'bush' so I can keep well away from most of it I hope. I think it is going to be a warm winter here.
Still 31.5 deg C.
Cheers

 

[NickAdams]

I added the Deere low voltage relay on my B2400. It has been well over 5 years ago and it still starts every time. Kubmech is the man.

 

[Strummer]

I just bought a B2400 that had the starter issue, after a quick search I found this thread. Just ran over to the JD dealer and picked the AM107421 relay- - -she's starting like a champ now.

Thanks All ! ! !

Going to have to try this fix

 

[MDCKubota]

Since last summer, when I tried to start the tractor, most times it would take up to 10 or so tries turning the ignition key on and off to finally start. With each try, I could hear the starter solenoid click. I cleaned the battery terminals, battery clamps, and ground connection to the frame. Problem not fixed. I then replaced the starter solenoid and that didn't fix the problem. Since I needed the tractor to start without fail for winter snow blowing, I had the Kubota dealer pick it up for repair. He replaced the starter switch and it started OK all winter. This spring, the problem started again. When I used jumper cables to start it, it would start OK. I assumed the 8 year old battery was bad so I replaced it. Problem not solved. I then temporarily installed new battery cables. Problem still not solved. Finally I read Kubmech 's posting on this problem (7/15/04). He explained that the increased resistance in starting circuit as the parts aged caused a decreased voltage to reach the starter solenoid. When this voltage decreased enough, the solenoid did not have enough current to engage. His solution was to install a low voltage relay which would engage and allow full voltage from the battery to engage the starter solenoid. Use of John Deere part AM107421 was recommended (Approx $18). Since I had tried almost everything else (and didn't want to have to send the tractor back to the dealer) I bought the part and installed it. Tractor had sat for about a week and started on first try. The part has been installed for over a week and the tractor has not failed to start on the first try. Installation is easy, it is almost as if this part was made for installation on a Kubota. Wires from low voltage relay plug right into the Kubota solenoid terminals and wire from ignition switch. (See Kubmech 's posting for detailed installation instructions). If you have this starting problem and cleaning the battery cable clamps, ground, battery terminals and your battery is good, I would suggest trying this part. The most you can be out is about $20. Wish I had read this posting earlier, it would have saved me about $350. Thank you Kubmech

When you had the problem starting your Kubota, did the engine turn over but would not start or did you just hear the starter solenoid click? My Kubota BD21F will turn over but it won't completely start. Any suggestions? Any advice you can offer would be much appreciated.

 

[MDCKubota]

I added the Deere low voltage relay on my B2400. It has been well over 5 years ago and it still starts every time. Kubmech is the man.

When you had the problem starting your Kubota, did the engine turn over but would not start or did you just hear the starter solenoid click? My Kubota BD21F will turn over but it won't completely start. Any suggestions? Any advice you can offer would be much appreciated.

 

[MDCKubota]

I finally got around to do the John Deere AM107421 relay kit modification to my B2400 after several years. My B2400 would not start the first several key turns. With this mod it starts on the first turn. Amazing!

The mod took about half an hour. Most of that time was spent deciding where to attach the relay. I decide to attach it to a support for one of the fan belt pulleys because it had an easily assessable bolt that also looked like it was grounded to the engine. Actual time doing the actual physical install was probably 5 minutes.

I'm posting 2 pictures with the mod. 1st picture shows the complete mod. 2nd picture shows how the relay is attached to the pulley support.

Thanks to Kubmech for discovering this mod

When you had the problem starting your Kubota, did the engine turn over but would not start or did you just hear the starter solenoid click? My Kubota BD21F will turn over but it won't completely start. Any suggestions? Any advice you can offer would be much appreciated.

 

[MDCKubota]

Going to have to try this fix

 

[Gruncle]

So...I finally visited the southern MD authority on all things starter/motor slash electric: Sr. Techn there told me: 1) This click and fail to trigger the solenoid is VERY common. 2) JD has a kit for sale specifically aimed at correcting the issue (as some have alluded to on this thread but I did not see that JD had issued it as a kit intended for this problem.) 3) He agrees that the issue arises because of marginal voltage getting to the primary side of the solenoid. 4) Commented that because the whole issue is marginal (not a big go-no go thing) many different actions affect it. He often takes off the starter, cleans all the contacts and puts it in top shape and that usually makes the problem go away. Says trying to locate which of the several safety interlocks is causing the most of the voltage drop is 'not worth the labor to chase it.' Almost any small 12v relay installed in the primary side for the solenoid cures the problem. He has installed several kinds. AND it is certainly not just Kubota. He has seen essentially every brand of small tractor with the same disease.

I tried the relay fix on my RTV1140 Kubota without any luck. The relay I used says its a 12V 40A, is that not considered a small 12v relay, could that be my problem? The engine still cranks once or twice and then click, click, click same as before the fix was installed.

 

[CADplans]

I tried the relay fix on my RTV1140 Kubota without any luck. The relay I used says its a 12V 40A, is that not considered a small 12v relay, could that be my problem? The engine still cranks once or twice and then click, click, click same as before the fix was installed.

Well, simply use a HEAVY piece of wire to bypass the relay (like welding cable)
If the tractor starts, the answer is that you need a heavier relay.

If you still get click, click, click,, then the relay fix is not what you need.

There are literally a dozen or more things that can cause the problem,,
time to do a little searching.

I have replaced OEM cables with welding cables, and fixed the problem.
Where the battery cable hooks to the tractor frame can be dirty,, a little cleaning can cure the problem.

A ground cable bolt can be loose,, simply tightening the bolt can fix the problem,,

The clamp at the battery post can be corroded,, and on, and on,, and on,,,,

 

[KubNuB]

I have been having this issue since getting an old G1800 and could REALLY do with some extra help in resolving this without putting in a bypass starter switch.
As with everyone else, same intermittent starting issue...
Have replaced the keyed starter switch, the starter motor and solenoid, battery, regulator, bypassed seat cutoff, checked and cleaned every connector I can find, installed the low voltage relay, cleaned the terminals and earth connections and still have the problem !
Everytime I replace or clean something it seems to be fixed, but after sitting for a couple of weeks BOOM back it comes !
Am starting to wonder if it could be an intermittent fault starting to occur in the "golden brain" ~ can anyone enlighten me on this before I spend another huge amount of $$ for nothing ?
Often it will start fine, ALWAYS after it has allready been running. If it wont start, there wont even be a click... turn key, wait for preheat light to go out, turn key further ~ nothing... sometimes hold the key in the start position for a while, 30 secs to 2 mins and it will magically start, other times have to put screwdriver across terminals and will start instantly ! Once I have done that, can turn it off and it will start straight back up or even a couple of hours later... I'm not great with electrics, and wonder if something in the control box is deteriorating and needs to have some power through it before it will work again, could this be possible ?
Have also just bought a little electronic voltmeter to start wiring in at each point of the circuit starting at the new relay and work back through each connector to see if I can isolate voltage drop that way as it would seem that there is no voltage going from the key when that happens, but holding the key over, or continually trying, mostly (eventually) works !

ANY suggestions would be appreciated, thanxs in advance !

 

[KubNuB]

A couple of further notes, I have noticed the seat bypass was unnecessary as it didnt matter whether you were sitting in it or not as to whether it would start or not, however the PTO and brake safety's definately effect it and must both be closed or it wont start. Hence I wonder if it is in the control box..
Also, I know the control box doesnt work correctly as the motor doesnt shut off if you leave the seat with the PTO engaged and wonder if this is the cause of the intermittent failure.. it is also strange that when it wont start without jumping the starter terminals, you can start it after that EVERY time for at least the rest of the day.
Auto electrician was somewhat stumped as well as they tried it everyday or two for a couple of weeks and couldnt get it to NOT start, they stopped when the bill got to a couple of hundred $ for nothing !
It does seem to occur most often after sitting for at least a week or two, but today happened several times while I was fixing a small fuel leak by replacing the "o" rings on the injector pump valves and trying to bleed the lines afterwards, very strange !

 

[Henro]

If I were you I would start a new thread. This one is old enough and long enough that many posters will not get to the end and your questions before losing interest...

Start a new thread with your questions. Might also visit the OTT (Orange Tractor Talk) site for additional help.

 

[Gator6x4]

A couple of further notes, I have noticed the seat bypass was unnecessary as it didnt matter whether you were sitting in it or not as to whether it would start or not, however the PTO and brake safety's definately effect it and must both be closed or it wont start. Hence I wonder if it is in the control box..
Also, I know the control box doesnt work correctly as the motor doesnt shut off if you leave the seat with the PTO engaged and wonder if this is the cause of the intermittent failure.. it is also strange that when it wont start without jumping the starter terminals, you can start it after that EVERY time for at least the rest of the day.
Auto electrician was somewhat stumped as well as they tried it everyday or two for a couple of weeks and couldnt get it to NOT start, they stopped when the bill got to a couple of hundred $ for nothing !
It does seem to occur most often after sitting for at least a week or two, but today happened several times while I was fixing a small fuel leak by replacing the "o" rings on the injector pump valves and trying to bleed the lines afterwards, very strange !

Trace the wire coming from the ignition switch to the starter. You will probably find a relay. In most vehicles the wire coming from the ignition switch to the starter goes to a relay. The small voltage coming from the ignition switch collapses the relay which in turn send true battery voltage to the starter relay which in turn activate the starter and spins the engine.

A poor ground at the relay will prevent the relay from collapsing and starting the engine. Make sure all the connections at the relay are tight and clean. If they are tight and clean you probably need a new starter relay.

 

[JWR]

Agree with Gator that it is a good idea to trace the wire from the switch toward the starter -- which the OP said he is about to do -- but I am not so sure he will find a relay in the original equipment. This thread has gone on so long I've lost certainty, but I thought he said that an added relay was installed to get full voltage to the solenoid bypassing the 6 or 8 small voltage drops for safety interlocks. If that is true I was amazed he still has the intermittent starting issues. He says if he uses a "screwdriver" to directly apply 12v to the solenoid she starts every time. That being the case I would bet that somewhere in the chain of many safety interlocks there is an intermittent failure -- a loose switch, a 'sometimes making contact' gadget. If the "hard start relay" was added (as I think it was) that still requires the degraded not-quite-12v- signal to get to the primary side of the relay to make it close. Not much current, not great voltage, but has to be adequate to close the relay.
So, I'm betting that somewhere in the interlock chain is an intermittent disconnect causing failure of the "start command voltage" making it to the primary of the relay. As he goes down the chain check every single one, jiggle it, try to make it fail and you'll probably find the culprit.