The starter motor operates on a high electrical current, converting it into mechanical energy to turn the engine over. This process is essential for the engine to begin running independently. As such, the proper functioning of the starter motor is vital for the overall operation of the vehicle.

The electric starter motor or cranking motor is the most common type used on gasoline engines and small diesel engines. The modern starter motor is either a permanent magnet or a series-parallel wound direct current electric motor with a starter solenoid (similar to a relay) mounted on it.