JD 855 help.

[hemiguy]

I think we are on the right track here. I agree its probably the hydro pedal ("neutral interlock"), PTO interlock, or related wiring. I used to have a similar 755 with the same problem. It happened once in a while, but I never took the time to fully diagnose it before I sold it. I think all of the interlocks tie into enabling the fuel shutoff solenoid on the fuel injection pump. It has the rubber boot on it and you should see it engage when you turn the key to start. I think this it turn, enables the starter solenoid. I used to have a repair manual for my tractor and recommend you look for one on Ebay or from the dealer. They are expensive ($100+) but a must have for an older, pre-enjoyed tractor. They have full electrical schematics which along with a test light and/or multi-meter should help you find the loose/dirty connection.

Good luck.

[855Idiot]

I "we" got into it this afternoon. Ripped everything off and followed the Purple wire from the key switch to the pedal switch and everywhere else.

Cleaned & tested every connector + switch along the way.

Tried the key and Magic!
Fired right up!
Several times in a row!

Still intermittently not starting though? I've got to be on the right track.

Amazing amounts of dust and dirt came out of each connector/switch.
All of the sensors were corroded and needed polishing/cleaning.

Things are looking up