Understanding Car Electrical System Components

By PSA Concepts Unlimited
Understanding Car Electrical System Components

The components and wires that make up a car's electrical system can be intimidating, but at their heart, cars have just a few electrical necessities. These components form the core of a car's electrical system, and you really need to understand them if you plan to comprehensively understand automotive electrical systems.

This system's core is its battery, a potent cell that stores and renders the energy crucial for activating the engine and energizing the electronic components that live on the vehicle. It's a rechargeable power source (obviously) that delivers the initial burst of energy necessary for cranking the engine, while simultaneously stabilizing the voltage for the vehicle's entire electrical network.

Tied to the battery is the alternator, which performs an essential function in keeping the charge up as you drive. When the engine runs, the alternator converts mechanical energy into electrical energy, ensuring that the battery stays charged and that all parts of the system receive a steady flow of power.

An additional key element is the fuse box, which protects against circuit overloads. The fuses are protectively placed to safeguard delicate components. When the current exceeds safe levels, fuses break the circuit instead of allowing excess current to continue flowing, and sometimes that means the fuse has to blow (figuratively speaking, of course) to prevent a disaster.

All these components are brought together by the wiring harness, through a complex maze of cables. Meticulous arrangement and shielding of the wires ensure effective, safe communication among the harness's constituents: every sensor, control unit, and electrical accessory. If you understand all this, if you understand even part of it, you can use that knowledge to help you diagnose common electrical problems in bad bugs. Blown fuses, burnt wires, and wiring routed through too many sharp corners are part of a landscape you can visualize.

In addition to these essential components, today's automobiles are fitted with high-tech electronic control units (ECUs). These computers control everything from fuel injection to the braking system (yes, it's in there), and in some cases, they have even taken over such mundane tasks as controlling the HVAC system in your car—a fact for which I am sure the designers of these units are not proud.

Much like the functions that ECUs perform, the process of understanding what is going on inside a control unit does function in layers. Maintain a basic understanding of control unit functions, and you will have a solid grasp of diagnostics and the maintenance process in general.

Tools Used for the ECU/DTC Process.