The starting, or cranking system consists of the battery, starter motor, ignition switch and related wiring. These components are connected electrically. When the ignition switch is turned to the START position (and the theft protection module recognizes the key code, as equipped) battery voltage is applied to the starter solenoid (through the theft deterrent relay, as equipped) S terminal and the solenoid windings are energized. This causes the plunger to move the shift lever, which engages the pinion with the engine flywheel ring gear. The plunger also closes the solenoid contacts, applying battery voltage to the starter motor, which cranks the engine.
When the engine starts, the pinion will over-run and spin at engine speed (rather than starter motor speed) to help prevent flywheel and starter motor damage. When the ignition switch is released (removing the voltage from the solenoid) the plunger return spring disengages the pinion. In order to prevent excessive over-run, the ignition switch should be released as soon as the engine starts.
Vehicles use several different types of starter motor applications. When obtaining a replacement starter motor, make sure you get the correct unit. In nearly every case, the starter motor is considered non-serviceable which means they are not user-serviceable and must be replaced as an assembly.
Starter motors do not require lubrication. In general, starter motors give little trouble. Most no-start or hard cranking complaints can be traced to a low battery, poor connections, defective fusible link, engine oil too thick for the weather conditions and other non-starter related causes.
Although different starter motors are used on different engines, the removal and installation procedures are very similar. The main differences are getting to the starter (air dam removal or radiator baffle removal requirements on some applications).