L5030 GST Dies when shifted forward or reverse

[hitech2002]

Ok, this one has me stumped. First time posting, but this forum has helped me many times.

We washed off the tractor yesterday and it now won't move. It was working fine until then. It starts and runs fine. I can start up the PTO, manipulate the front loader, use the aux hydraulics, but when I shift into gear (forward or reverse) with the clutch depressed it stalls. If I shift without using the clutch it will jerk and stall. My first thought was the seat switch...checked it...working fine. I also checked the connector on the proportional valve and it is clean and well seated. It also doesn't act like the seat switch in that it will die even if the clutch is pushed in. I can hear a click (like a relay) under the dash when I shift, but I think that is normal. If I idle up and shift into gear it will stall. If I shift back to neutral quickly it will recover and continue to purr.

I am thinking safety switch somewhere or the proportional valve is bad. Any help would be appreciated.

 

[gpreuss]

The seat switch should work two ways - it should allow just the PTO with the seat folded up, and everything with the driver pushing the seat down. Sounds like maybe the internal contacts are stuck in the seat-folded-up position. (I don't know if this is even possible...) Depending on what you were doing, maybe while washing you got a small twig or piece of grass in the contacts? Or possibly you've knocked one of the wires loose?
I'd figure out which wires get joined together by the driver being in the seat, and jumper them together.
As you've said, it sure sounds like the seat switch, except for the PTO. Maybe it uses a different set of contacts in that switch.

 

[North Idaho Wolfman]

Cab Or ROPS model?

 

[hitech2002]

It is a ROPS Model.

I will check the switch again. It has 3 contacts in it. When when the switch is disengaged (noone in seat) pins 1 and 2 complete the circuit. When engaged (butt in seat) pins 2 and 3 complete circuit. I assumed based on this behavior that the switch is working. I will pull up the wiring diagram to confirm.

 

[North Idaho Wolfman]

Check the connection on the ECM Left side below the seat, also check the GST position connection just on the top of the transmission.
I have heard both of those can causing problems.

 

[hitech2002]

I checked and cleaned all of the connectors. It is still doing the same thing. It appears that the fuel shutoff solenoid is engaging when I put it in gear. Even when in neutral I shift forward or reverse and about 1 second after I shift i hear a click and the engine stalls. It really seems like there is some kind of kill situation going on. I really dont think it is the seat switch as it appears to change state and generally as long as the clutch is pushed in you can shift forward or reverse and the engine will continue to run. I know this because my son is too light to activate the seat switch and tried to drive previously. As long as the clutch is pushed in the engine would run. As soon as he would release the clutch it would stall. This stalls when shifted whether the clutch is pushed in or not.

I am really stumped here. The engine purrs like a kitten, no bogging down and all of the hydraulics are working great, so I have just about ruled out a flow issue. I can roll it fine, so brakes aren't frozen. Cleaned and reseated all connectors that i would think could even might cause an issue. Checked the battery and alternator and they are working fine (trying to rule out even the wierd ones).

I am starting to think GST position sensor or proportional valve issue. I just don't know if those could cause this. Any thoughts? I am guessing at this point.