How Do Starters Work?

Your Semi-Truck's Starter and You.

If you've read our article on steps to take prior and during installation of the starter motor, then you're probably wondering what comes next. To continue our series, we'll be discussing semi-truck starters and starter solenoids. So, how does a truck starter work? In this article, we'll be discussing the ways in which your starter operates and how it fits into the overall system of making sure your vehicle starts as expected.

Read on to learn more about the starter motor in your commercial vehicle!

What is a starter?

What is a starter? First of all, today's starter was designed to be used as a rotation tool in an internal-combustion engine, initiating the engine's operation. Modern starters are available in electric, pneumatic, and hydraulic models. Especially in the case of large engines, or diesel engines in semi-trucks, the starter can also be another internal-combustion engine.

Internal combustion engines are developed to be a kind of feedback system. Once started, they use motion from each stroke cycle to initiate the next. For example, in vehicles that use a four-stroke engine, the third stroke releases energy from fuel, powering the exhaust as well as the intake and compression strokes. It also powers the external load of the engine. Starting the cycle at the beginning of any session, the first two strokes must be powered by the engine. The starter motor is used for this purpose and is not necessarily needed once the engine starts running and the feedback loop becomes perpetual.

A Brief History of the Starter Engine

Prior to the invention of starter motors, engines used various methods of starting up including wind-up springs, gunpowder cylinders, or removable crank handles which engaged the front of the crankshaft. In 1903, Clyde J. Coleman invented and patented the first electric starter in America. The idea was that a relatively small motor, driven with higher voltage and current than would be needed for continual operation, could deliver enough power to crank the engine.

How Does a Starter Work?

You may be curious as to how exactly a starter works to get your semi-truck moving. The answer is simpler than you might think.

An electric starter will take electrical energy from a battery or capacitor and convert it into torque at the starter's pinion gear. The pinion then engages with the ring gear which turns the flywheel and rotates the engine's crankshaft.

When you switch on the ignition, the starter motor is powered, and the electromagnet inside the body of the starter turns on. This pushes out the rod the pinion where the gear is attached. The gear meets the flywheel, and the starter turns. This spins the engine over, sucking in the air and fuel your semi-truck needs to run properly.

How to Troubleshoot A Starter

There are several ways in which to determine whether your starter has gone bad as opposed to your battery or alternator. A few ways to tell that your starter has gone bad include:

1. Engine won't turn over: One of the most common signs that your starter has gone bad is that your engine won't turn over. The probable cause is that the starter relay or motor has burned out, either that or there is an electrical problem.


2. Clicking, grinding, or whirring: Another obvious sign that your starter has gone bad comes when your turn your key and you hear a clicking, grinding, or whirring sound accompanied by your motor not switching over.


3. Issues Starting the Vehicle: Simply stated, if your vehicle won't start you may want to check on the quality of your starter.


4. Starter Engages But Motor Won't Start: You may hear the starter activate, but the motor doesn't crank over, this is an indicator that your starter isn't working.

Read More!

In order to provide you with the most information possible, our experts have put together several articles on the topic of starting your commercial vehicle. Take a look at the following articles to learn more!

1. How Does An Alternator Work?
2. Starter and alternator troubles.
3. Match Made starters and alternators.
4. Is my alternator or starter failing?

Shop Starters Today!

If you are looking for a brand new or remanufactured starter for your semi-truck, then you've come to the right place! We have a multitude of options for you to choose from developed by all of your favorite manufacturers. Shop starter motors and alternators today!