Starting System: Description and Operation

INTRODUCTION

Starting System Component/Wiring:

The starting system has:
- Ignition switch
- Starter relay
- Clutch pedal mounted starter interlock switch with manual transmission
- Wiring harness
- Battery
- Starter motor with an integral solenoid.

These components form two separate circuits. A high amperage circuit that feeds the starter motor up to 300+ amps, and a control circuit that operates on less than 20 amps.

CIRCUIT OPERATION
Power for the solenoid in the engine starter motor is supplied on circuit T40 from the engine starter motor relay. This circuit connects to the contact side of the relay from the engine starter motor.

Power for the contact side of the relay is supplied by circuit A1. This circuit is protected by a 40 amp fuse located in cavity 19 of the Power Distribution Center ([1][2]PDC). Circuit A1 spliced and provides battery voltage to the ignition switch, and HOT at all times.

The ignition switch supplies battery voltage to the coil side of the engine starter motor relay on circuit A41 and F45 when the key is moved to the START position and the operator has pressed the clutch pedal to CLOSE the clutch pedal position switch. Circuit Z12 grounds the coil side of the engine starter motor relay when the coil side of the relay energizes, the contacts CLOSE connecting circuits A1 and T40, supplying battery voltage to the engine starter motor solenoid.

Circuit A0 (battery positive cable) supplies battery voltage to the motor of the starter when the solenoid energizes.

The engine starter motor, used in this vehicle is case grounded to the engine block.