Enrolled in Auto Mechanic School? Here’s How Car Electrical Systems Work!

Auto Repair Career

The best auto mechanics know that a car is only as good as its electrical system. While a powerful engine gives a car the ‘wow’ factor,  a solid wiring job can mean the difference between a reliable, efficient auto and a ‘lemon’ that gives its owner constant headaches.

The electrical system of a car powers its starting and ignition circuits, lights, and sensors, as well as accessories such as the car’s heating, radio and navigation system. With modern automakers developing more and more complex electrical systems, a solid understanding of how a car’s electrics work is more important for auto mechanics than ever.

Get a head start on your auto mechanic training with this brief overview of car electrical systems:

Auto Mechanics Should Understand the Basics of Electricity

For students pursuing auto mechanic careers, the best way to get to grips with electrical systems is to understand the basics of how electricity works. It can seem complex at first, but it is actually relatively easy to understand.

Electrical charges are carried from one place to another through wires from a power source. The force or pressure of the electricity running through the wire is known as voltage, while the speed that the charge travels at is called the current, which is measured in amps. Multiplying the two together gives us the wattage, which tells us how powerful the charge is.

This determines the resistance (how thick the wires need to be) needed to prevent components from overheating or burning out.  Fuses are also installed, which are short lengths of wire encased in glass, to absorb high current.

A Beginner’s Guide to Auto Electrical Systems

Auto Mechanic School

Current needs to flow from a power source to the device it needs to power, and then to an earth component, which absorbs the electrical charge to neutralize it. The car electrical system starts at the battery, and flows through each component of the car it needs to power. The system is earthed by the body of the car itself.

A Car’s Ignition Powers Its Electrical and Mechanical Systems

Students in auto mechanic school quickly learn to identify which car problems are mechanical and which are electrical. The ignition system, however, is trickier, as it has elements of both.

The ignition switch’s first function is to provide a charge to turn on the electrical system. Most electrical components of a car, apart from headlights and tail lights, are wired directly through the ignition switch, to stop drivers from leaving things switched on by accident and draining the battery.

The starter motor is also connected directly to the battery by its own heavy cable. This system also includes the alternator, which generates power and recharges the battery. The starter motor uses energy from the battery to generate horsepower to get the engine moving for a few hundred revolutions, at which point it continues to run by itself.

Auto Repair Student May Encounter Common Electrical Problems

Auto Mechanic Careers

Electrical problems can affect many different parts of a car, but once you understand how electrical systems work, you’ll find that the issues affecting each area are all fairly similar. Here are some the most common problems to look for:

  1. Electricity can only flow one way (usually positive to negative), so check if the component is wired in the right direction.
  2. Wiring that is too thin can cause components to overheat or burn out, so replace the wiring if needed.
  3. Surges of high current can blow fuses, so check the fuse box and replace them if necessary.
  4. Check that switches and relays of the electrical system are wired correctly.

Would you like to learn more about car mechanics to better prepare yourself for a successful auto repair career?

Visit ATC for information regarding our training programs or to speak with an advisor.

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