Starter Feedback

sounds like a ignition switch issue not stopping the flow of electricity.

So check the wiring harness in the truck.

well yes, but the switch may be bad.

Does your model have a solenoid mounted on the firewall near the battery? Check for proper operation. You can also disconnect the voltage wire from the solenoid to the starter then turn the key to the "on" position. If there is voltage from the terminal on the solenoid leading to the starter then the solenoid could be the problem. Next check the voltage wire to the solenoid (small wire). If voltage is present with key in on position, check backward toward the ignition. If no voltage, but voltage out to starter, then solenoid is stuck. Replace.