Starting System: Description and Operation

Fig. 1 Exploded View Of Starter Motor. Conventional w/Manual Trans:

Fig. 2 Exploded View Of Starter Motor. Reduction w/Automatic Trans:

Nippondenso starters, Figs. 1 and 2, are either a conventional type or reduction gear types. The conventional type used on manual transmissions consists of a frame and field assembly, an armature assembly, an overruning clutch assembly, a starter solenoid assembly, a commutator end housing, a brush holder and a shift lever. The reduction gear type starters used on automatic transmissions which use all of the above components along with a reduction gear and shock absorber assembly.
When the ignition switch is turned to start and the clutch start/neutral safety switch is closed, the solenoid windings are energized, resulting in plunger and shift lever movement. This causes the pinion to engage the engine flywheel ring gear and the starter solenoid contacts to close. With the contacts closed, the starter solenoid provides a closed circuit between the battery positive terminal and the starter motor. The starter motor is grounded to the engine block, therefore the circuit is complete and engine cranking may occur.
Once the engine starts, the pinion is designed to overrun and protect the armature from excessive speeds until the ignition switch is released from the start position. When the ignition switch is released, a return spring in the solenoid assembly opens the starter solenoid contacts, breaking the circuit and disengaging the pinion.