Q: How Does the Alternator Work in Your Car?

If the vehicle’s battery is the heart, its alternator would be comparable to its lungs. Both systems must work together to start and keep your vehicle running for years. The alternator is responsible for supplying power to all electrically powered components in a vehicle while the motor is operational. Before the engine starts, this responsibility falls on the battery. Once the driver turns the key and starts the motor, the alternator is activated and takes over for the battery.

How does an alternator work?

The alternator is typically installed in the engine compartment and is powered by a belt called the serpentine belt. In some cases, the alternator has its own belt called the alternator belt. When the engine spins over, a series of pulleys that are attached to the engine’s crankshaft are spun, which in turn spins the belt that is attached to another pulley on the alternator. The pulley attached to the alternator is connected to a needle bearing that spins around a series of metallic coils and generates electricity. There are also voltage regulators that control the amount of electricity produced. The electricity is distributed from the alternator to a series of relay switches, fuses, and connectors that supply power to components on the vehicle. The alternator is constantly working to generate electricity while the engine is running. Due to this fact, there are several factors that impact the lifespan of the alternator, which makes it very difficult to predict exactly how long it should last on a car, truck, or SUV. In some cases the alternator will work as long as you have the vehicle. In general however, the alternator should last anywhere from 50,000 to 100,000 miles on most domestic and import cars, trucks, and SUVs.

There are a few signs that might alert you that the alternator is wearing out, including: * The headlights seem dimmer than usual * Dashboard lights are not as bright as they should be * The ALT or GEN light illuminates on the dashboard * Accessories such as radios, AC and auxiliary switches don’t work as well

These symptoms are common with an alternator that is wearing out. If it breaks or the alternator belt is broken, the vehicle will quickly drain power from the battery and eventually shut the vehicle off or make it impossible to start. If this occurs, you’ll need to contact a local ASE certified mechanic and have them complete an alternator replacement or alternator belt replacement to get your vehicle back on the road.