Your Trusted Auto Repair Shop for 40+ Years
Shop Talk Logo

How Does Your Car Start?

To keep your car running well, it is helpful for you to have some knowledge of how the different components of your car work. Your vehicle’s starting system may seem confusing at first, but any driver can learn how it works and why it’s important to keep it maintained.

How Your Car Starts

Most vehicles today use an electric starting motor. This system consists of five main parts:

  • Battery
  • Ignition switch
  • Starter relay
  • Battery cables
  • Starter motor

When all of these parts work together, your car starts.


Your vehicle’s battery provides the electrical current needed for your car to start and also supplies additional electricity when needed. When you put your key into the ignition and start your car, the current begins flowing.

Ignition Switch

This component allows electricity to flow where it is needed. The system has five switch positions. The start position is the one that supplies electricity to the ignition, sending the electrical current to the starter relay.

Starter Relay

The starter relay receives the small electrical current sent by the ignition switch and converts it to the larger current needed to start the motor. It is set up this way because, although cars need large electrical currents to start, the ignition switches and wires would need to double in size to hold a current that large.

Battery Cables

Your battery cables are multi-stranded, large wires. They carry this larger electrical current into the starter motor.

Starter Motor

Your starter motor has two gears on it. When the electrical current reaches the motor, they mesh together as the motor spins the engine. As fuel and spark are introduced into the cylinders this is ignited, thus, the engine starts. As the engine begins to spin faster than the starter, a gadget called the Bendix drive separates the starter and the engine, and the starter disengages.

How to Maintain This System

Although you don’t think about your starting system often, it still needs some maintenance. Your car’s battery needs to be cleaned and inspected occasionally. Electrolyte condensation and corrosion naturally build up and need to be removed. Your wires and electrical cables should be inspected for breakages or fraying. It is also important to inspect your alternator belt for cracking or fraying. Your technician can inform you best on the condition of your starting system.

Do you think your starting system might need a tune-up? Call or stop by one of our Sun Auto Service locations and ask us about your vehicle today.