Truck only starts once

Hello, I think the start solenoid is staying energized after you release the key from the start position. This would cause the gear to stay engaged on the flywheel, and the starter would be running as the engine runs. This, or the grounding strap for the engine is trashed, which is causing damage to the starter as there is no other grounding point.

My problem was when the Ford dealer checked battery cables they hooked up wire from solenoid to fuse box and alternator wires up to the hot on the solenoid, wire to starter stayed hot all the time. But it would crank once!