Starting System Principle of Operation: Solenoid: Notes

The Solenoid performs the following functions:

• Pull the pinion to engage the flywheel
• Hold the pinion engaged with the flywheel during starting rotation.
• Complete the electrical circuit from the battery to the brushes of the starter.
• Cause the pinion to retract from the flywheel.

Fig 1: Identifying Solenoid Switch Assembly Components

Courtesy of BMW OF NORTH AMERICA, INC.

Two windings are used to pull and hold the pinion engaged to the flywheel.