Starter Motor: Description and Operation

The starter motor is a 12-volt unit that has the starter solenoid mounted on the drive end housing.
^ The motor is energized when the starter solenoid contacts are closed.
^ This engages the starter drive with the flywheel ring gear, starting the engine.
^ An overrunning clutch in the starter drive protects the starter motor from excessive speed when the engine starts.
^ The current flows through the solenoid energizing coil until the solenoid plunger is at the end of its travel.
^ The plunger then closes a set of contacts that bypass the energizing coil.
^ The holding coil keeps the starter drive engaged and passes starting current to the starter motor.