3930 will not sart

Jerry/MT · Feb 14, 2011

jinman said:
Yes, there are two separate safety systems. One is neutral sensing and the other is operator presence. My tractor does exactly as you said. If you are operating and stand up, the engine dies. You can crank the engine, but it won't start. If you put the range in neutral and set the parking brake, you can stand up because that bypasses the operator presence system. When the OP said his tractor was cutting out while his neighbor operated it, that sounds to me like a defective seat switch on its last legs and making intermittent contact. That's exactly the symptoms that I would expect.

I'm making an assumption that the 3930 is very similar to my tractor in operation since it seems the safety circuits are similar from the original post. As easy as it is to check the seat switch, that would be my starting point because I know it is common for NH to disable the fuel solenoid.

Thanks for the explanation. i thought there had to be some additional logic to sense operator presence besides just the seat switch.Ii would have been surprised if something as old as a 30 Series Ford would have had that.

Thanks again.

jinman · Feb 14, 2011

Jerry/MT said:
Thanks for the explanation. i thought there had to be some additional logic to sense operator presence besides just the seat switch.Ii would have been surprised if something as old as a 30 Series Ford would have had that.

Thanks again.

Jerry, I know a lot about Boomers, but sometimes making the leap to using the same logic on older tractors gets me into trouble. I just think it's very important to realize when I am wrong, admit it, and move on. I hope I'm always able to do that.