General Information
This service information describes the principle design and function of a starter motor, regardless of the make.
The starter motor (6/25) cranks the engine to make starting possible. The starter motor is located on the transmission side of the engine block. The exact location depends on engine type. A solenoid causes a pinion to mesh with the crown wheel on the engines flywheel/carrier. When the engine has started and engine speed exceeds starter motor speed, the pinion disengages. This prevents overcranking of the starter motor.
The starter motors are equipped with either permanent magnets or electro-magnets (field windings). DV6 S/S and the V8 engine have field windings.
The starter motor gives the greatest torque at low RPM at the same time as the voltage current through the starter motor is greatest.
The engagement time for the starter motor must not exceed 20-30 seconds. Longer engagement time results in the starter motor overheating and becoming damaged.
A starter motor relay (2/35) controls the starter motor solenoid. The starter motor relay is controlled by the engine control module (ECM).