Starter

How do motor starters work? A starter is essentially a very powerful twelve volt motor that is designed to turn over your cars engine to allow it to start. When you turn the key on your ignition, twelve volts goes to the solenoid on the starter motor. This solenoid does two things. It allows voltage to go to the starter motor itself, which causes it to spin and it also engages a gear on the shaft of the starter motor which meshes with the fly wheel on the engine, and so when the fly wheel engages the starter motor gear, it turns with the starter motor. Now once the engine is running and you release the key, the solenoid retracts and the gear disengages from the fly wheel and the engine is running. Some signs of a starter motor failing may be that the gear does not engage the fly wheel, in which case you would hear a whirring sound, but the engine would not turn over. If the starter motor doesn't turn over at all, it could be a bad starter motor, but it could also be a dead battery or a bad cable or a bad ground connection. The best way to test a starter motor is to hook up a connector directly to the starter motor to bypass the cable and verify that there are not issues in the wiring harness.