JD 6403 Blown ignition fuse

[jrice0728]

My 6403 has blown an ignition fuse and will not turn over. No other issues. It is sitting where I parked it yesterday when I returned from the hay field. Could this be a Neutral safety switch fault?

 

[TBN Support]

Hi and welcome to the forum! I have moved your thread so that it can get more views. Best of luck with your 6403!

 

[Dave M7040]

Is it not a diesel?
If so, it would not have an ignition fuse. Where did you get the fuse name from?
Do you have a wiring diagram you could post?
Dave M7040

 

[jrice0728]

Thank You

 

[jrice0728]

Yes it is a diesel and it is labeled Key Switch in the operators manual. I unplugged the Injector pump wires and the temperature sensor wires. I replaced the fuse and it started. I cannot find a bare spot on the wires Not sure what is going on. The tractor has less than 600 hrs. Ran great yesterday. I spent all day today trying to get it to do anything besides run the headlight and honk the horn. I just started trying to eliminate thing. Fuse was blowing in the run position. I though the only thing getting current in that position was the injector pump and engine sensors. Not sure what I did ? Will a faulty temperature sensor cause the key switch fuse to blow?

 

[JD5210]

Based on what you described, I believe the problem is the thermistor sensor (thermistors are temperature variable resistors used as sensors.).

When the sensor fails it shorts out and blows the fuse. As you have already determined unplugging it and replacing the fuse, it starts and runs. The part # is RE503242, if you do not already know it I have included a link to JD parts catalog.

John Deere - Parts Catalog

 

[jrice0728]

Thank You I will give it a try