I have a 1992 F-150 and can't figure out was is wrong with it. I recently started the truck fine but go to a jobsite and the ignition switch turned but would not turn the engine off. after that, it would not start or turn the motor off. I pulled the coil wire to stop the motor and pulled the ignition switch from the steering column and found that the back tail piece on the old switch was broken off so I purchased another one. After replacing the switch with the new one, the new switch DOES start the engine but still will not turn it off and I still have to pull the coil wire to stop it. Does anyone know what I am doing wrong!!! HELP!

 

welcome to FTE.
did you try adjusting the new switch? there is a little movement in the switch mount to slide it up or down on the column to get the positions to line up with the key cylinder.