Talk about going back in time...

Sorry I can't help, but maybe start a new thread din the appropriate section for a faster response.

but I'll go with the sensor needs to be swapped for a proper one...

 

Do you have and know how to use a digital multimeter?

One of a few things is happening:

1) The ignition switch or steering column wiring for the switch is malfunctioning

2) Something else is putting 12V on the purple wire that energizes the starter relay coil and passes power to the started. This would most likely be a wiring short or the trans range switch

3) something is putting 12V on the starter power wire. This would not be enough to start the truck but might kick the started gear into the flywheel.

While not the most likely, the easiest to rule out is #1. Start the truck and then pull the crank fuse and see if this keeps happening. If it still happens then its not the ignition switch or its wiring out to the relay box.

Report back and we will keep going if its not the ign switch.


George