Circuit Operation - Starting System

When the ignition switch is moved to the START position, battery voltage is applied to the starter. Both solenoid windings are energized. The circuit through the pull-in winding is completed to ground through the starter motor The windings work together magnetically to pull in and hold in the plunger, which moves the shift lever. This action causes the starter drive assembly to rotate as it engages with the flywheel ring gear on the engine. At the same time, the plunger closes the solenoid switch contacts in the starter solenoid. Full battery voltage is applied directly to the starter motor, which cranks the engine.

When the solenoid switch contacts close, voltage is no longer applied through the pull-in winding, as battery voltage is applied to both ends of the windings. The hold-in winding remains energized, and its magnetic field is strong enough to hold the plunger, shift lever, drive assembly and solenoid switch contacts in place to continue cranking the engine.

When the ignition switch is released from the START position, battery voltage is removed from the circuit 6 wire and the junction of the two windings. Voltage is applied from the motor contacts through both windings to ground at the end of the hold-in winding. However, the voltage applied to the pull-in winding opposes the voltage which was applied when the winding was first energized. The magnetic fields of the pull-in and hold-in windings now oppose one another. The return spring causes the drive assembly to disengage and the solenoid switch contacts to open simultaneously. As soon as the contacts open, the starter circuit is turned off.