How Does a Starter Motor Work?

Without a functional starter motor, you and your car are going nowhere. But how exactly does a starter motor work and why do you need one?

For a car’s engine to work, it needs two things: air and combustion. When the car starts, it sucks in air. This air is used to combust the fuel in the car. To get the air into the engine, it needs to turn over. Early car designers recognized that getting the air into the engine required a special mechanism. Enter the starter motor. The starter motor turns the engine over so that it can function.

Within seconds, a starter motor performs five different functions so that your car can start. Let’s have a look at each one in detail.

Step One – Engaging the triggering switch

The second the key is turned in the ignition the car battery is stimulated. The battery works the triggering switch. This allows the electrical energy to move from the battery to the starter solenoid. Now it’s clear why a car with a flat battery can’t start. If there’s no current moving from the battery to the starter solenoid, the engine can’t get going.

Step Two – The starter solenoid

A solenoid is a coil of wire. It is shaped in a cylindrical form. The solenoid acts as a magnet when charged with electrical current. A starter solenoid’s job is to provide current to the starter motor. The starter solenoid is found above the starter motor. When the car is starting, the starter solenoid receives an electrical current from the battery. The current causes a pair of contacts in the solenoid to close. This allows the transfer of a larger electrical current to the starter motor.

Step Three – The starter motor is awakened

That second current sent from the starter solenoid to the starter motor switches on the electromagnet. The electromagnet is housed inside the starter motor. This magnet is essential as it facilitates the operation of the pinion gear.

Step Four – The pinion gear emerges

The electromagnetic force inside the starter motor pushes the pinion gear out of the starter motor. The pinion gear is quite small. It emerges from the starter motor and engages with the flywheel.

Step Five – The flywheel turns

The pinion gear, as tiny as it is, operates the much larger flywheel. The flywheel is a gear attached to the car’s crankshaft. The flywheel begins to turn. This operates the pistons in the engine. They begin to move up and down. This motion sucks air into the engine. The engine senses the arrival of the air and releases fuel. The fuel combusts and your car’s engine springs to life.

We take for granted that each time we turn the key, the engine will start. In fact, it’s such a delicate process that it’s easy to see why things can go wrong. Just one faulty or worn out part can derail the entire process. Keeping your starter motor in good shape is essential if you want your car to be reliable.

Tips for caring for your starter motor:

1. Make sure that all the connectors aren’t corroded, dirty, or grimy.
2. Clean the solenoid and the terminals so that the connections are not compromised.
3. Make sure the pinion gear and flywheel aren’t damaged.