JD 4200 HST Starts but engine shuts off when engaging forward/reverse

[Surveyor4200]

Good morning TBN. My JD 4200 HST has had an intermittent issue that now seems to be here to stay. After starting (no issues) attempting to engage forward/reverse on the HST will shut the engine off, just like if I leave the seat. I checked the seat safety switch, found it to be in working condition and jumped it anyways. When attempting to run PTO, the engine also shuts off (just like the seat safety switch, again). I know there is a PTO safety switch also, but if it had failed, I would assume the tractor wouldn't even start? I'm not the best at reading wiring diagrams, but from what I can tell, the neutral switch would not allow the tractor to start if it has failed. Again, the tractor starts just fine.

Backstory on current issue: I was operating the tractor just fine, hauling some firewood, parked up by the house to help the wife carry in groceries (this is where I get to blame her so I can get a new tractor 'it was fine before I helped you'), returned to finish hauling the firewood and current issue arose. I have had this happen intermittently before, but after a few pedal press/release before engine shutoff, it would work again.

 

[dodge man]

The seat safety switch could be fine but it could be in the wiring going to it. I would try to trace the wiring and look for a problem, like a break or short. Just a guess on my part since it sounds like the seat safety switch.

 

[zzvyb6]

I believe there is also a pedal position switch. My friend's 4400 won't start it the pedal rocker is not in a 'neutral' movement position. I presume this prevents you from starting off with a wild ride. This might be related to the difficulty you are having.

 

[ovrszd]

Hmmmm..... Thinking outloud....

The PTO switch should cause a non start situation...

The pedal position switch should cause a non start situation...

My old 2210 has a range lever switch, has to be in neutral to start. Again, it causes a non start situation...

My old 2210 would die if I had engine running and pushed an HST pedal without being in the seat. You could start the engine without being in the seat. But engine would die if you pushed a pedal without being in the seat. I jumped the seat switch and resolved the issue...

I'm running out of ideas. Are you positive your seat switch bypass is working? Maybe mess with the bypass jumper wire? Or maybe even cut the wires and solder them together?? I always hate to do mods that I can't easily reverse...

Really got my curiosity up. Post resolution when you figure it out please.

 

[WranglerX]

Really sound like system does not know you are actually in seat, so my guess would be seat switch or any other safety switch down stream from seat switch or crummy corroded connector or actually broken connector or wire....

Have you looked at electricals to be sure you don't have rodent (mouse/rat) chewed wiring....

 

[Surveyor4200]

Really sound like system does not know you are actually in seat, so my guess would be seat switch or any other safety switch down stream from seat switch or crummy corroded connector or actually broken connector or wire....

Have you looked at electricals to be sure you don't have rodent (mouse/rat) chewed wiring....

This is my suspicion, also. I was just wondering if there is another 'downstream' safety switch that would act like the seat switch. Looking at the wiring diagram, I really can't tell. I assume I can break my jumper connection and test the voltage at the joint to see if there's a connectivity issue. The tractor sits outside, and I have no shortage of field mice/squirrels other rodents.

 

[dodge man]

So for going off topic. Are you a land surveyor? I still have my license but retired about 2.5 years ago.

 

[Surveyor4200]

So for going off topic. Are you a land surveyor? I still have my license but retired about 2.5 years ago.

Yes, sir! So you understand then: when you're a surveyor, you've got to be a mechanic, a painter, a carpenter, etc. for the times when work is slow! Congratulations on retiring! I've been licensed for a little over 12 years at this point and about another 20-25 to go (hopefully).

 

[dodge man]

Funny you say that, my experience exactly. You forgot computer expert also. I got my license in 1992 at 29 years old.

Good luck with the tractor, I’m betting a wire problem with the seat switch. Did I say I hate wiring problems?

 

[Surveyor4200]

Funny you say that, my experience exactly. You forgot computer expert also. I got my license in 1992 at 29 years old.

Good luck with the tractor, I’m betting a wire problem with the seat switch. Did I say I hate wiring problems?

Yes, I did forget computer expert; luckily I have a good staff that work for me (although NONE of them can help with mechanical issues).

I feel like it's a wiring issue also, especially starting off intermittently. I agree about wiring problems-much disdain for them.