JD 4200 Safety Interlock System

[JLF2010]

As I was mowing pasture, my JD 4200 hydrostatic tractor suddenly shut off. When I turned the key to try starting it again, the starter wouldn't run and I didn't hear the click of the fuel shut-off solenoid. I checked the fuses and found that a 10 amp fuse for the safety interlock system was blown. So I replaced it and tried starting the tractor again. The starter still wouldn't run. (The oil light and battery light turn on, so it's not a battery issue. I also disengaged the PTO lever, put the shift lever in neutral and engaged the park brake.) I checked the interlock fuse again, and it was blown, so I'm guessing a wire must be shorting out somewhere. I traced some of the wires that I thought were part of the safety interlock and couldn't find bare wire. I wasn't able to trace it under the hood. Does anyone know where the wires lead to under the hood? Or any other suggestions?

 

[beenthere]

:welcome:

There have been some wiring diagrams posted in the recent past on TBN. Try a search in the Deere forums and see if any threads appear to be related.

When I'm trying to track a short down that blows a fuse, I make up a 12v bulb on a couple wires to insert into the fuse block (not sure how that would work with the Deere fuse block right off-hand). But tracing and looking for a short is a lot easier this way, as the light bulb will stay on if there is a short.

 

[JLF2010]

Thanks for the reply! I tried using the 12V lightbulb with wires attached to insert into the fuse block to see if the light would turn on. It didn't turn on, but I could hear the click of the fuel shut-off solenoid. I was trying to locate the solenoid to see if I could trace the wires back to the fuse block, but I couldn't figure out where it is. Does anybody know? So, I removed the nuts holding the fuse block in place to see what color wires (red) are used for the safety interlock, but couldn't find that color and size red wire under the hood. So, I decided to put everything back together and put a new fuse in the fuse block to see what would happen. It started right up and ran fine. I mowed with it for a couple of hours without any problems. So, it's a mystery why the fuse blew in the first place and why the first new replacement fuse also blew.