JD 4300 puzzle

[Dentbla]

New member, first post. I have a JD 4300 HST. When I step on forward or reverse pedal, it dies. When I engage rear PTO. it dies. I have bypassed the seat safety switch, I have replaced the switch that is activated by the forward/reverse pedals, and the two neutral safety switches. Fluid levels all good. Now for the fun part...if I pull up on the hand brake, the PTO will engage. If I bypass the forward/reverse pedal switch, the tractor will drive. Cleaned the fuse box area and pulled all fuses/relays out and cleaned terminals. I also switched the relays around as they are all the same, no luck. Front loader works fine and three point hitch raises and lowers.
I am lost for ideas...please help me!
Thanks in advance.

 

[jthibodeau89]

Sounds like the safety circuit is cutting the power to the fuel solenoid. Perhaps a damaged wire? Do you have a manual with the electrical diagrams?

 

[TractorGuy]

My guess is the wiring to the seat switch is damaged making it open even though you bypassed at the switch.

 

[Dentbla]

Sounds like the safety circuit is cutting the power to the fuel solenoid. Perhaps a damaged wire? Do you have a manual with the electrical diagrams?

Thanks 89, I traced the wiring harness looking for anything questionable, but I guess a damaged wire would be like finding a needle in a haystack. I just have the schematics available on the JD web site. Do you know if the switch on the lever brake is part of the safety circuit?

 

[Dentbla]

My guess is the wiring to the seat switch is damaged making it open even though you bypassed at the switch.

Thanks TG, is there a way with a meter to confirm a damaged wire?

 

[joecdeere]

Check your private messages

 

[jthibodeau89]

Thanks 89, I traced the wiring harness looking for anything questionable, but I guess a damaged wire would be like finding a needle in a haystack. I just have the schematics available on the JD web site. Do you know if the switch on the lever brake is part of the safety circuit?

Ill check my manual.

 

[jthibodeau89]

Yes, the parking brake switch is part of the safety circuit. "If trans in neutral, pto disengaged, , then set park brake, operator can leave seat and then re-engage pto." So park brake seitch will allow the ptp to be engaged without operator in seat.

From the manual:

"Engine must stop is pto engaged and operatpr leaves seat"

"Engine must stop if transmission is engaged and operator leaves seat"

It sounds like your sear switch wiring may be the culprit

 

[dodge man]

I had a car I restored years ago with a bad wire for a power window. I gave up trying to find the break and just ran new wires. Still a pain but it did fix it.

 

[Dentbla]

Thanks everyone for sound advice. I got a schematic so will be checking everything this weekend.