425 will not shut off

[Greenblood2011]

It's probly easier to just trace the wire... Deere puts there diodes any where they fit. It'll most likely be small about an inch square with two wires that plug in. Could be black or yellow. Check and make sure he didn't bypass the seat switch, that could also cause this issue. Let me know what you find.

 

[beenthere]

Update
Just heard that

....... it was the starter relay and diode. Not sure which failed first but they both had to be replaced.

Wanted to see this to some kind of closure.

 

[Gittyup]

so was the starter runing all the time?

 

[regalgsguy]

Hello all. I am restarting this thread cause my 425 is not shutting down too. I can completely disconnect the key switch and board from the tractors harness, turn on the pto switch without sitting on the seat and the engine continues to run. That diode "rectifier kit" that goes in the tractors harness, where exactly does it go? Is that diode for engine shutdown? The tractor is a early serial 425.

 

[beenthere]

:welcome: to TBN

You say "early", is s/n older than 033626 ? If so, then maybe need to check out the "carburetor vent solenoid". If newer than that s/n, then check out the "fuel shut-off solenoid".

 

[regalgsguy]

The serial is in the 12000 range so it has a vent solenoid. The solenoid tubes have been disconnected and the carb revented directly to the airbox with a new tube bypassing the solenoid due to it having heat up failure. The only way I can stop the engine is by disconnecting the little red power wire from the battery positive lug on the starter to the time delay module. Turning off the key switch does shut off everything but the engine ignition circuit.

 

[Richard001]

Looks like it's time to replace the delay module and the diode that is closest to the seat switch.

Richard

 

[regalgsguy]

For twenty bucks it is worth a try replacing the time delay. Should I assume the diode near the seat switch is buried in the harness somewhere? Is this problem common in JD's? I work on 100's of craftsmans and other cheap tractors every year and know the electrics like the back of my hand, but these JD circuits I have yet to study and fully understand.

 

[regalgsguy]

Its been awhile since I replaced the module and can confidently say that was the problem. All is well now.

 

[Richard001]

Good to have success and closure.

Good job.