Starting System: Description and Operation

CRANKING CIRCUIT
The cranking circuit consists of the battery, starting motor, ignition switch, restart relay and related electrical wiring. These components are connected electrically as shown in the image.

STARTING MOTOR
The starting motor has field coils mounted in the starting motor yoke (frame). The magnetic switch assembly and parts in the starting motor are enclosed in the housings so that they will be protected from dirt and water. In the circuit the magnetic (motor) switch coils are magnetized when the ignition switch is closed. The resulting plunger and pinion clutch movement causes the pinion to engage the engine flywheel gear and the magnetic switch main contacts to close, allowing cranking to take place. When the engine starts, the pinion overrunning clutch protects the armature from excessive speed until the switch is opened, at which time the pinion will disengage.