How does Vehicle Electrical and Lighting work?
Your car has a lot of electronics onboard. When you operate the radio – that's the electrical system. When you roll your power windows down, yep, that's the electrical system, too. And of course, your car's lights operate off the electrical system, as well.
Would you believe all of these electron-hungry components rely on two primary parts: the battery and the alternator? It's true. The battery supplies power to your car's electronics anytime the engine is off. For example, it's the battery that supplies juice when you're listening to the radio in your driveway.
Then, when your engine is running, the alternator takes over. The alternator, which is driven off the engine by a belt, converts mechanical energy into the electrical energy needed to power your car's electronics. At the same time, it charges the battery, so your car will be ready the next time you want to hang out and listen to the radio in your driveway.