When it comes to powering your car’s radio, headlights, and other electronic components, you may think it’s the battery that’s putting in all the work. In reality, it’s your alternator that keeps things up and running. But what exactly does an alternator do and how does it work? Read on to find out what makes your alternator so important and how to recognize Car alternator problems before they become a major issue.
WHAT DOES AN ALTERNATOR DO?
While the battery is essential for starting your car when it’s off, the alternator keeps your car alive when the engine is running. The alternator powers most car’s electronic components while you’re driving around or idling, including your headlights, electric steering, power windows, windshield wipers, heated seats, dashboard instruments, and radio. The alternator supplies all of them with direct current (DC) power. Your alternator is also responsible for charging your car battery while driving.
The alternator works by turning mechanical energy into electrical energy. When your engine is on, it powers a drive belt that rests on a pulley attached to the alternator. The pulley turns the alternator’s rotor shaft, which spins a set of magnets around a coil. These spinning magnets generate alternating current (AC) around the coil, which is then channeled to the alternator’s rectifier. The rectifier converts that AC power into DC power, which activates your car’s electrical systems.
Alternators typically last the lifetime of your vehicle, but that doesn’t always happen. General wear and tear, heat damage, overuse, exposure to water, faulty parts, or frayed wires can put your alternator out of commission before your car heads to the scrap yard.
WARNING SIGNS OF A BAD ALTERNATOR
Without a working alternator, your car won’t start in the near future or stay on for more than a few minutes. Yet the typical signs of a bad alternator are often mistaken for problems with the battery or other car parts that display similar symptoms. In other words, if you’re experiencing only one of the issues below, your alternator may not necessarily be the issue. However, any of the following warning signs may indicate a potential issue with your vehicle’s electrical system. Bring your car to your local Motor Sport Co to have your electrical system inspected so we can get to the root of the issue.
DIM OR OVERLY BRIGHT LIGHTS
When an alternator begins to fail, it provides inconsistent voltage to your electronic accessories. Generally, that takes the form of under- or over-performing equipment, like headlights that are either too dim or extremely bright. You may also experience flickering lights or lights that erratically go from bright to dim and vice-versa.
DEAD BATTERY
Sometimes a dead battery is just a dead battery — it’s reached the end of its life after a few years of use — or maybe you accidentally left the headlights on all night. Other times, however, a dead battery could be a sign that your alternator is malfunctioning.
A bad alternator won’t sufficiently charge the battery while the engine is running, causing the charge in the battery to deplete faster than usual. One way to test whether the issue is battery- or alternator-related is to jumpstart the car. If you jumpstart your car and it stays running, your battery may need replacing soon. However, if you Jumpstart the car and it dies again shortly after, it may mean your alternator isn’t getting enough power to the battery.
SLOW OR MALFUNCTIONING ACCESSORIES
An alternator that isn’t supplying enough power to your car’s electronics often results in slow or non-working accessories. If you notice your windows taking longer-than-usual to roll up or down, or if your seat warmers aren’t heating quickly, or even if your speedometer and other instruments start going haywire, you may have an alternator problem.
Many modern vehicles also have a priority list of equipment programmed into the car that tells the onboard computer where to cut power first if the alternator isn’t supplying enough electricity. That way, if you’re driving with a failing alternator, you’ll lose power to your radio (or other nonessential accessories) before losing power to your headlights.
