i read someone else had this problem and I did not see where they found a solution. "The key lights up instrument lights ,fuel pump hums, glow plugs light up, but will not crank, Horn has been disconnected and seat switch bridged. I can put the key in the run position and arc the starter motor, and it will start and run perfectly. when i try to turn it off the key has no affect and i have to manually push the motor cut off lever to kill it. Safety switches all test OK, the 3 relays all test OK, the fuses seem to be OK, Battery terminals tight and earth lead to chassis tight. Seems to be the ignition switch but it will not hotwire if the ignition switch is in the off position, and the fuel pump turns on with the first stop and the glow plugs with the second, but no crank on the third." I have this exact same issue and have done these exact same steps. If anyone has or knows the answer please let me know.
Thanks
Thanks