What Is an Alternator?
The alternator is one of the three major components that make up a vehicle's charging system. (The other two are the battery and the voltage regulator.) It looks like a small cylindrical generator that is usually bolted to the engine.
The name "alternator" doesn't quite capture its purpose, so let's break it down for you. In short, an alternator is a generator that works while the car is running. The electrical system of any internal combustion engine car is powered by these devices, converting mechanical energy into electrical energy. In short, the charging system consisting of the alternator, battery, and voltage regulator is responsible for generating, supplying, and regulating electricity. The alternator converts mechanical energy into electrical energy via alternating current (AC). The alternator is usually bolted near the front of the engine and is driven by the crankshaft via a serpentine belt.
The alternator also plays an important role in the car's starting process. Without the alternator, the same would happen to the car battery (unless you're prepared to remove it from the car and charge it overnight every time). This clever component uses the electricity it generates to charge the car's battery, whether the car is moving or idling on the side of the road or in traffic. The next time you turn the key in your car's ignition, don't just thank the battery, thank the alternator, too.
Where is the alternator in your car?
You'll most likely recognize it first by the belt hooked to it, which is used to generate the power needed by your devices. The alternator is usually located under the hood of your car and is connected to the engine. The alternator is actually quite large, with vents around the entire circumference of its round body. Drive a truck? The alternator is in a similar location.
What does the alternator do?
The battery is key to starting your vehicle when it is turned off, but what is the alternator in your car for? The alternator powers key components such as headlights, dashboard lights, power windows, radio, air conditioning, and other electrical devices while you are driving or idling. It powers the battery and electrical systems to ensure that the vehicle operates properly when the engine is running.
It is equally important to charge the car battery while driving, ensuring that the battery is always ready for the next start.
How to Test a Car Alternator
If your alternator isn't working properly, but you don't want to spend money on repairs, here are some ways to do some tests on your own to evaluate its performance. Here's how:
Get a multimeter. Next, adjust the settings - the DC voltage (DCV) should be above 15. Next, connect the multimeter (engine off) - find the positive and negative terminals of the battery and connect the corresponding wires. The multimeter should now show a reading of 12.6. Once the engine starts, the reading on the multimeter should increase to between 14.2 and 14.7. Readings below 14.2 mean the alternator is undercharging the battery, while readings above 14.7 mean it's overcharging. Next, turn on the lights and the vehicle's electronic equipment. Finally, disconnect the power, turn off everything, including the engine, and check that the multimeter reading remains above 12.6.
How long does an alternator last?
Normal wear and tear, heat damage, overuse, exposure to water, faulty parts, or frayed wires can render your alternator useless before your vehicle reaches the salvage yard. But normally, your alternator should last the lifetime of your vehicle, providing reliable power to your car's electrical system. Watch for signs that your alternator is failing, which may mean you need to get it repaired.
What happens when your car's alternator fails (do they fail suddenly)?
If your alternator fails, you'll most likely be aware of it, as it can cause serious damage to your car's electrical system. Thankfully, there are symptoms you can watch out for if your alternator starts to fail, but in some extreme cases, it may fail completely and the only thing you can do is replace it.
Without an alternator to charge your battery, your car's driving time will be limited, and sooner or later the battery will die, leaving you completely stranded. You may not even be able to start your car at all, as the alternator provides the power to the spark plugs to ignite the fuel - without it, you're stuck.
They can also be damaged in an accident, which can cause the alternator and many other parts to need repair. In this case, it may be more beneficial to simply scrap your car.
