Description

CIRCUIT OPERATION

When the Ignition Switch is moved to the START position, battery voltage is applied to the Starter Solenoid 5 terminal from the Starter Enable Relay and the Gear Selector Switch (Automatic Transmission) or the Clutch Start Switch (Manual Transmission). Both the Hold-In and Pull-In solenoid windings are energized. The circuit through the Pull-In Windings is complete to ground through the Starter Motor. The magnetic fields created by the parallel circuits of the Hold-In Windings and the Pull-In Windings work together to pull in the Starter Solenoid Plunger. The Plunger moves the Shift Lever which causes the Drive Assembly to engage the Flywheel ring gear on the engine.

When the Plunger is fully pulled-in, the solenoid switch contacts close. The closing of the solenoid switch simultaneously controls two actions. Full battery voltage is applied to the Starter Motor through the battery cable, and it cranks the engine. At the same time, battery voltage is applied to the motor terminal side of the Pull-In Winding. With battery voltage on both sides of the Pull-In Winding there is no current flow through the winding and it no longer generates a magnetic field. The magnetic field of the Hold-In Winding is sufficient to hold the plunger in while the engine is cranking.

When the Ignition Switch is released from the START position, battery voltage is removed from the Starter Solenoid terminal S and the junction of the two windings. Current now flows through the solenoid switch to the motor terminal and through the Pull-In and Hold-In Windings in series. The magnetic fields oppose each other and can no longer hold in the Plunger. The Return Spring causes the Drive Assembly to disengage and at the same time opens the solenoid switch contacts. As soon as the contacts open, all electrical circuits in the Starter Motor are turned off.