# Kubota engine stop solenoid



## pointer33 (Oct 15, 2008)

Long time Lurker here, rarely post but now have a question. Kubota B7510 tractor, the engine stop solenoid fuse keeps blowing. It is 30difficult amp. 1st time was just bush hogging and killed motor. Bought new fuse and installed it a couple days later....started right up. Today bush hogging again...after a couple of hours it happened again.....installed new fuse....it blew while cranking motor. Briefly looked around for damaged wires etc.....any thoughts other than spending awhile tracing wires for a short that only occurs if vibrated just right?


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## agmantoo (May 23, 2003)

The coil in the solenoid could be partially shorted thus increasing the amp draw. Is the coil itself replaceable? Remember if the battery voltage starts dropping the amperage will rise. With the engine not running what is the battery voltage? Can you read the amp draw of the engine stop solenoid while the engine is running?


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## pointer33 (Oct 15, 2008)

Agmantoo, thank you for your thoughtful response. I am pretty slow in doing things right now do to many irons in the fire but here is what I have done. Battery with engine not running is 12.6Volts. I ordered a new engine stop solenoid ( which apparently cuts off fuel flow), I installed the solenoid....pretty tough to squeeze fingers in there but did it  
Went to start motor after installing a new 30 amp fuse for the engine stop solenoid....discovered another fuse had blown....a 30 amp fuse near starter that I am soon to look up what it is called but it cut off all power to the dash/starter. SO then it fired right up...happy happy happy....let it idle, went inside for a couple of minutes and when I came out I raised the bush hog and dumped the water out of the FEL and put it in gear to back up.....got about 6 feet and the 30 amp fuse to the engine stop solenoid blew again...leaving me again where it will crank but not fire off....acting like no fuel getting there again..... he he he...I am just smiling right now. I am kind a parts changer type mechanic and am a bit over my head. I have already given a brief look over the wires and seen no damage to the looms encasing them. 
If you are suggesting by your post that low batter voltage might cause higher amps.....I am on my second battery since 2005. Wouldn't this have happened the first low battery I had....or maybe I do not understand....

I am going to buy more fuses, and do more thinking....that solenoid was pretty pricey  I probably should have tried to to test the old one more but it seemed to present as a transient problem as I initially was able to mow more after the first fuse change....then the tractor seemed to be less reliable, sometimes blowing a fuse before starting when being cranked.....:shrug:


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## NW Rancher (Mar 8, 2008)

Typical diesel stop solenoids are three wire units. They use high current from the starter circuit to pull the plunger and then low current to hold a magnetic latch that holds the plunger open until it's shut down. I'm reaching here, but perhaps you have a fault in your starter solenoid that is staying engaged while running, sending high current to the stop solenoid, and blowing either the stop solenoid or start solenoid fuses.

Just a thought. Good luck.


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## pointer33 (Oct 15, 2008)

NW Rancher, I just looked and I have 2 wires going to m y engine stop solenoid....does that mean that your idea would not be the case? I realise it is a basic question and you may not want to spend half a day educating about the basics but is there a good way for me to check for a fault in the starter solenoid that may show up intermittantly....other than just replacing it?
As far as reaching...sometimes that is what it takes....had a mazda pickup when i was a teen and it ran very rough for a bit....2 shops said....uhh...third one a guy walked out....hit the air cleaner pretty hard with an open hand...the motor changed pitch...he said...ai/fuel solenoid....fixed it..he said he knew because he owned one and it happened to him....so reach away!


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## NW Rancher (Mar 8, 2008)

That doesn't mean for sure it's doesn't have two powered leads, it may be chassis grounded. I'd start with a voltmeter from each lead to ground during start and run cycles, see what you have for voltage to verify that neither is ground. If it's got two circuits like I describe above you should see voltage on both during start and only one while running. If they are both hot, next step would be a DC clamp meter to try to see what kind of current you are pulling through those during start/run.

As I think about it though, I'm going to back up a little and say that in most cases when fuses are blowing there is resistance somewhere causing voltage drop/amp rise. I'd start by checking every termination for rust, corrosion, loose wires, dirty connection, etc. Replace any bad looking fittings, clean all contacts, then start troubleshooting the solenoids if things continue.


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## pointer33 (Oct 15, 2008)

Agmantoo and NW Rancher, I appreciate your input. I am pretty slow at getting around to things, but the tractor is fixed and I figured I ought to post on here so that others might benefit from my issue as well...first off let me paint the picture a bit more....when all is said and done I checked for various issues you gents suggested and had already purchased a new fuel cutoff solenoid..being the parts changer I am.....so after all of that when the tractor woudl still cut off when trying to start or move it depending....I by that time had observed a total of three different fuses in different fuse blocks blow at different times. Here comes the HUMBLE PIE...I double checked the wiring looms for literally about the 10th time....this time I found the culprit....two wires bare from some welding I had done about 20 hours ago on the engine counter. Aparently they had jiggled over time to a position where they could sometimes short sometimes not....so I am feeling pretty small for taking so much effort to solve this without sufficiently doing the basics. I had looked at the wires multiple times but somehow was just blind to the damage....incredible.....I am slowly getting out of the parts changer mentality. So far with our cars....I am ahead...I have saved my family money over what I have spent but this solenoid I did not need sure stung! So any fellas out there that know less than me...learn my lesson..take your time and be slow to go for the sure fix 
Thanks again to your two that attempted to assist me in this!


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## Staceylee (Jul 12, 2020)

agmantoo said:


> The coil in the solenoid could be partially shorted thus increasing the amp draw. Is the coil itself replaceable? Remember if the battery voltage starts dropping the amperage will rise. With the engine not running what is the battery voltage? Can you read the amp draw of the engine stop solenoid while the engine is running?


Mine does same thing except mine blows the fuse just turning key on. Only started this after I washed radiator and engine compartment off


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## Staceylee (Jul 12, 2020)

pointer33 said:


> Agmantoo and NW Rancher, I appreciate your input. I am pretty slow at getting around to things, but the tractor is fixed and I figured I ought to post on here so that others might benefit from my issue as well...first off let me paint the picture a bit more....when all is said and done I checked for various issues you gents suggested and had already purchased a new fuel cutoff solenoid..being the parts changer I am.....so after all of that when the tractor woudl still cut off when trying to start or move it depending....I by that time had observed a total of three different fuses in different fuse blocks blow at different times. Here comes the HUMBLE PIE...I double checked the wiring looms for literally about the 10th time....this time I found the culprit....two wires bare from some welding I had done about 20 hours ago on the engine counter. Aparently they had jiggled over time to a position where they could sometimes short sometimes not....so I am feeling pretty small for taking so much effort to solve this without sufficiently doing the basics. I had looked at the wires multiple times but somehow was just blind to the damage....incredible.....I am slowly getting out of the parts changer mentality. So far with our cars....I am ahead...I have saved my family money over what I have spent but this solenoid I did not need sure stung! So any fellas out there that know less than me...learn my lesson..take your time and be slow to go for the sure fix
> Thanks again to your two that attempted to assist me in this!


Mine blows engine stop/solenoid fuse just when turn key on any ideas. Only started this after I washed engine compartment and radiator out with water hose


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## nosqrls (Jun 9, 2012)

either fuel solenoid or relay can be bad. bet on the relay being bad.


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## 101pigs (Sep 18, 2018)

Staceylee said:


> Mine blows engine stop/solenoid fuse just when turn key on any ideas. Only started this after I washed engine compartment and radiator out with water hose


Had a friend that had one. It quit every time he used it. Took it back to dealer (4 times) no return of money so he sold it for half price and got a New Holland. I have two New Holland. Best brand of tractor i have had.


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