most the DP40s I have seen have a time delay module, that actually supplies a b+ to a solenoid for a few seconds as the key is turned off, this pulls a solenoid to kill the motor, which releases after the motor has died and oil pressure went down and alt out put ended. the normal spring loaded "at rest" state is with the motor linkage in the run position, and the energized solenoid pull the linkage to shut off the motor.