JD 425 Electrical

[CPJD445]

I have a JD445 and two 425 's (All below SN 71000) that have served me well.
Recently, both 425's have presented odd problems-
425 #1- engine cranks non-stop on "RUN". Ignition seems not to fire, or Fuel Pump may not be pumping, but that is secondary.
My son was pulling a trailer and ran out of gas. I re-fueled, and went to start it and the engine kept cranking with the key in the "RUN" position.

425 #2- Mid PTO will not engage.
Tractor starts and runs fine.
Seat and brake switches test OK, as the tractor will not start or run when the appropriate switch changes state.
PTO light on the dash does not illuminate.
Existing PTO switch tests OK, I replaced with a new and a used switch to no avail.
Pre- 71000 production has fewer circuits thru the PTO switch, but still makes/breaks two circuits simultaneously.
I cleaned the terminals on the ignition relay board, connector contacts were corroded, but no solution.
rang out the PTO solenoid- tests OK. Dash Light does not illuminate either.
Starting to feel it's the ignition board with soldered in place relays.
Any way to test before I spend a couple hundred for the ignition switch/board assembly?

 

[radios1]

for #1, ignition switch. for #2, you'd have to trace the power to the PTO on the board using the wiring diagram and a voltmeter..

 

[Richard001]

JPCD,

Welcome to TBN
:welcome:

Richard

 

[CPJD445]

for #1, ignition switch. for #2, you'd have to trace the power to the PTO on the board using the wiring diagram and a voltmeter..

Thank you for the quick reply.

 

[CPJD445]

for #1, ignition switch. for #2, you'd have to trace the power to the PTO on the board using the wiring diagram and a voltmeter..

Thank you very much.
Tried the new ignition switch in both tractors. Took care of the issue with 425 #1. I did notice a bit of grease and a lot of dirt caked on the back of the control board. and some rust on the leads of some of the resistors. I'm in the process of cleaning the board and testing the relays to see if I can rebuild the board. Maybe circuits shorting thru the dirt/grease?

Unit 2 still misbehaving with the new ignition switch. I'll keep tracing circuits with the existing board/switch.

 

[CPJD445]

Anyone have a wiring diagram for a -71000 (non RIO) 425?
I find many 71000- (with RIO) wiring diagrams online, but not the earlier version.

 

[joecdeere]

I have a PDF of complete technical manual with wiring diagrams for the low serial # 425, if wanted message me your email

Joe