A Blue tractor problem

[Leon Torkelson]

I have a Ford 3600, a misfit around 12 farmalls. I am having a problem with the ignition switch. It starts and runs as long as I hold the key in the start position, whenI let the key go back to the run position the tractor it quits like it was shut off. I changed the switch but it acts the same. any ideas or previous problems like this. Thanks in advance.
 

[old]

I was going to answer you in the ford forum but since I see it here I will here. Good chance the ballast resister is bad since it starts and runs as long as you hold the switch. Many engines are set up to by past the resister so as to give a stronger spark for starting
 

[Bob M]

Leon - Most likely the problem's a failed (burned out) ballast resistor.

The resistor is wired between the ignition switch and the coil and gets bypassed when the ignition switch is in "start". Thus the engine fires when cranking but quits when you release the switch back to "on".
 

[Janicholson]

Some Fords may have a resistor wire in the ignition circuit rather than a discrete component. If when the ignition is turned to ON, there is no voltage at the coil, and you find no object as a resistor, it could be the wire itself. Jim
 

[cchigg]

sounds like a bad ballast resister if it will run with the key in the start position and when you let go to the run position it will shut off like you turned the key off.don't bypass it or it will fry the points.