Starters - MOTORCRAFT: Operation

Turning the ignition switch to the "START" position activates the solenoid. The solenoid then connects the battery to the starter.

When the starter is not in use, one of the 4 field coils is connected directly to ground through a set of contacts. When the starter is first connected to the battery, a large current flows through the grounded field coil, activating the movable pole shoe.

The pole shoe, attached to the starter drive plunger lever, forces the drive assembly into the flywheel ring gear. When the movable pole shoe is fully seated, it opens the field coil grounding contacts and the starter operates normally. A holding coil is used to maintain the movable shoe in the fully-seated position while the starter is turning the engine.