Key Stop Fuse?

[jcri]

I recently bought a used L4310. I noticed there was a missing 15amp fuse labeled “KEY STOP”. The tractor seems fine with or without it. The difference is that WITH the fuse, I hear an audible click whenever I cycle the key.

Can anyone explain what this is for? I tried searching and found previous threads where people talk about blowing these fuses, but nothing that explains my circumstance. My tractor starts and stops with or without it. Like I said, the only difference is the solenoid sounding ‘click’ with the fuse present. I’m wondering if the reason it was out was related to a problem the previous owner had and maybe he did something to bypass it or similar? Just trying to understand. Thanks guys.

 

[aczlan]

There should be a solenoid that pulls the fuel shutoff lever for 10-20 seconds after you turn the key off. That is probably what that fuse is not. No idea why it would shutoff without the solenoid though.

Aaron Z

 

[s219]

I am amazed the engine would start and shut off without that fuse in and the solenoid working. Doesn't make sense at all.

 

[ericm979]

Is there also a mechanical shutoff that's triggered by moving the thottle past the idle position? My old B7100 had that.

 

[diesel85]

The newer engines have an electronic solenoid that controls a mechanical shutoff.

IIRC, that is there to prevent a fuel-based runaway.

 

[David_Kb7uns]

If the engine has only a keystop solenoid, no power needed to energize solenoid to start. Some engines have a dual solenoid that has a coil to run and a coil to stop.

My D782 and D902 is keystop but my D1105 has the dual solenoid.

 

[radios1]

the tractor shouldn't run without that fuse!. I think it was rigged, because the fuse kept blowing!. there's a lot of post that say it's a common problem for that fuse to blow unexpectedly.. Blowing a 5 amp "key stop" fuse - OrangeTractorTalks - Everything Kubota

 

[s219]

the tractor shouldn't run without that fuse!. I think it was rigged, because the fuse kept blowing!. there's a lot of post that say it's a common problem for that fuse to blow unexpectedly.. Blowing a 5 amp "key stop" fuse - OrangeTractorTalks - Everything Kubota

Yeah, but he only hears the solenoid "click" with the fuse in. So the fuse hasn't been bypassed, it seems.

 

[jcri]

Ok, now I’m even more confused. After putting the fuse in and removing it, the behavior has changed.

Let me explain:
- when I opened the fuse panel this morning the spot for the 15amp key stop fuse was empty. So it had been empty for the few weeks that I’ve owned the tractor and I’ve started and obviously stopped it a dozen times.

Today, I inserted a 15amp fuse in that blank and tested it and as I said in my opening post, staring and shutting down worked fine and actually no different the without the fuse. Just the solenoid click sound can be heard when the fuse was used.

Later today, I removed the fuse and started the tractor... HOWEVER NOW... the tractor engine will not shut off when I turn off the key. I had to insert the fuse while it was running to be able to shut it off.

So... clearly the previous owner had done something to rig this, but I’m even more perplexed now assuming that my inserting this fuse has ‘undone’ whatever was rigged... ??

 

[s219]

Well, that is confusing for sure. I'd put the fuse in and live with it for a while. If the fuse blows, don't do anything until you look over all the wires in the harness and check for shorts or worn insulation. More times than not, when this particular fuse blows it's because there is a short somewhere.