Tractor Won’t Turn Off By Key Ignition – Why & How to Fix?


You are done working with your tractor and you turn the ignition key off. However, to your surprise, the engine remains alive. Is this somewhat similar to the kind of situation you are in now? If so, we can sort this out.

There can be multiple reasons why you are facing this. But solving it will require you to start by looking into the battery. If the issue is not solved, check the fuel shut-off solenoid. If that is yet no help, fixing the wiring and ignition switch will hopefully solve the problem.

Whichever reason it is, don’t sweat it. Maybe this is your first time but the engine not shutting down with its key is a typical issue in tractors as they run on diesel engines. Also, we are here to help. All you have to do is follow the steps in this article and you will be able to fix it in no time.

Why Causes Tractor Won’t Shut Off With Key Ignition?

Why Causes Tractor Won't Shut Off With Key Ignition

As we have said earlier, there can be several reasons behind this issue. But for whatever reason you have this issue, it has to be closely related to one component- that is the engine. Below we have listed some of the most common reasons why you are facing this issue.

  • Battery might not be functioning right.
  • Fuel shut-off solenoid might have gone bad
  • Damaged wiring on the connector switch
  • Ignition switch might be damaged
  • Fuse might not be functioning right

5 Solutions for Tractor Not Shutting Off with Key Ignition

Every diesel engine tractor- let it be a Kubota, Sears ST, or Murray, would come with a shut-off solenoid. The solenoid is like a little rod on or near the fuel pump connected via a wire to the tractor’s motor. A temporary fix is to push the solenoid to kill the engine for now. 

It is only a half-fix because manually shutting it off can entirely be a hassle. Now that you have the engine off, let’s hop on into some real action, look into the issues listed above, and fix them right away. So let’s get your gears started.

1. Battery Issue: Replacing it

Battery Issue: Replacing it

The battery helps in providing energy to power the tractor’s engine. However, a malfunctioning battery might continue to supply juice to the engine even after cutting the power with the key, for which the engine stays active.

So to solve the battery issue, it is advised that you visit the service center and take a little help from an expert. But if you want to go for a replacement, it is very much possible to do it all by yourself.

To replace the battery take a 10mm wrench and remove the negative terminal before the positive terminal. Make sure that the terminals don’t touch one another or any metal. Remove the holder on the battery and pull it out. Then simply place the new battery in and connect the terminals.

Depending on its type, fixing the tractor battery from a service center can cost around $45-$250 with the parts and mechanic charge. However, replacing it yourself can cost you around $35-$120.

2. Bad Fuel Shut-off Solenoid: Cleaning or Replacement

Bad Fuel Shut-off Solenoid: Cleaning or Replacement

To test whether the solenoid has been damaged, we need to check on the voltage across it. If there is no voltage across the solenoid in the off position,  then it can be said that the solenoid is stuck in the open position. In this scenario, the solenoid needs to be cleaned or replaced.

So the solenoid is right at the bottom of the carburetor. Start by putting a fuel clamp on the fuel pipe before we start cleaning it. Take a ½-inch wrench and detach the solenoid. Now use the WD-40, spray it on the plunger and clean it off. Set it back and check if it solves the problem.

For replacement, you don’t require any additional instructions. Just use the wrench and unbolt the old solenoid before setting the new one in.

Cost of cleaning it yourself can be a max of $10, which is the price of WD-40 itself. In case of replacement, the price of a new solenoid can cost you about $20-$45, depending on the type of solenoid needed.

3. Damaged Wiring on the Connector Switch: New Wiring

Damaged Wiring on the Connector Switch New Wiring

It is a usual scenario for the kill wire on your tractor to be physically damaged. This could be one of the reasons why your tractor is not shutting off with its key.

To confirm the wiring issue, test the polarity on the ignition switch between ground and magneto. Afterward, check the polarity of the tab on the ignition to the spade connector to your kill wire. Whenever the reading drops, be sure to check on that connection.

Now it is advised that you take help from an expert or visit the service center to change the wiring. But to do it on your own, use a heavy gauge coil to your screw connection. Remove the wire from the screw, start the engine and then short the coil wire to the ground.

The cost associated with wiring problems can range from around $30-$60 depending on which connections you are having issues with.

4. Damaged Ignition Switch: Replacement

Damaged Ignition Switch: Replacement

The ignition switch is a mechanical component. So it isn’t quite atypical that your ignition switch malfunctions or stops functioning. The best move when something such happens is to replace the switch.

It takes only 15 minutes to replace the ignition switch. All you need is the new switch, wrench set, and work gloves. The first step is to turn the ignition switch off and remove the key. Remove the bolt connecting the negative cable to the battery and tuck the battery cable away. 

Lift the hood to access the back of the ignition switch. Release the locking tabs and push the switch out through the front of the dash. Disconnect the wire harness attached to the back of the ignition switch. Connect the wire harness to the back of the new ignition switch and set it back in.

Depending on the manufacturer of the tractor, an ignition switch can cost you around $30-$40, while you can easily replace it on your own following the steps above.

5. The fuse might not be functioning right: Time for a new fuse

The fuse might not be functioning right: Time for a new fuse

If you are already done checking on the factors mentioned above, it is about time that we look over the fuse. 

In the case of Sears Craftsman, the fuse is usually tucked away in the wiring harness. On the other hand, Kubota BX moderately has its fuse box inside the cover underneath the dash. Rotate the knob and access the fuse box. Using a multimeter check whether it has blown off.

Now fixing a fuse issue is easy. All you need to do is- pop back a new, fully functioning fuse and you are good to go. 

Finding a fuse is no big deal. They are available all across the internet and are relatively cheap around $5-$10.

How To Test Your Tractor After Fixing It?

How To Test Your Tractor After Fixing It

There is no such methodical approach to testing your tractor. All you can do is start the engine, wait for it to heat up, and then try shutting it down using the key. Going on test drives is also a good idea. 

If your issue is fixed, your tractor should be shutting down right after switching the key off.


Below we have collected the most frequently asked questions related to this topic “why isn’t my tractor shutting off with its key?”. We hope that this section helps you to get a better idea and guides you to fix it.

Can the solenoid be manually used to shut off the engine when the key isn’t doing the job?

Yes, it can be and there is no harm in doing so. However, it can get quite frustrating to shut it off manually all the time for which we advise that you follow this article and work on the fix.

If the battery is dead, should I use my car’s battery to charge it?

Yes, you definitely can. However, before doing so, check that the battery is dead with a multimeter. Or else you could be damaging a functioning battery. Be careful while connecting the terminals to avoid sparks and not to mention that a high amount of voltage could get you electrocuted.

The tractor still does not shut off with its key after applying the fix. What to do next?

In this article, we have covered the most plausible causes as to why you are having this issue. However, there could be many more. If your tractor is still not fixed, we advise that you visit the service center because it would be complicated to solve without an expert’s help.

Is it safe to drive while this issue is still active? 

No, it is not safe. The truck being unable to shut down may seem like a mere issue. However, it indicates that there is something wrong with your tractor. This, in the future, could cause severe, permanent damage and even unfortunate accidents.


Such small issues can result in bigger problems if left unfixed. So it is advised that you don’t brush this problem off. Just open up the hood and grab your toolbox. Following this article, you will be done in no time.

Still having doubts? We assure you that fixing this will take you only about an hour. And the steps in this article will direct you toward success. But if you are still worried, visiting the service center will be no big deal.

So the next time your tractor is not shutting off with its key, you know what exactly to do. Also, we’ll be right by your side. Give this article another read if needed. Take small steady steps. We know you got this.   

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