Starter Motor

It engages the flywheel ring gear with a small pinion. Start-stop cars use reinforced starters or belt starter-generators. Modern starters use a reduction gear so a small, fast motor can produce high torque. They draw several hundred amps for a few seconds.

A solenoid pushes the pinion into mesh and closes the high-current circuit.

A click without cranking can mean a weak battery, bad connection or worn starter. Slow cranking is more often caused by the battery or the cables than by the starter itself, so these are tested first.