Signs You Need to Replace Your Alternator
Oftentimes, your car's alternator will go out with little or no warning. But there are a few signs to look out for that can alert you the alternator may die.
David Waits owns a 1999 Toyota Land Cruiser with 245,000 miles on it.
In all those years — and miles driven — Waits, owner of highly rated Japanese Automotive Service in Hilliard, Ohio, says he’s never had a problem with the vehicle’s alternator.
But not every driver is as lucky when it comes to her or his alternator.
“Mine’s still going strong,” Waits says. “They typically last a long time, but some cars need new ones after 50,000, 60,000 miles.”
How your car’s alternator works
The alternator, which is located on the engine, provides power to the battery and continuously charges the battery and the car’s electrical systems and computers.
“It’s a hard-working part,” says Jeff Gunning, service manager with highly rated Addison Auto Repair & Body Shop in Denver. “Its primary job is to keep the electrical system up and running in place of the battery. The battery’s job is to start the car, and the alternator keeps it running.”
Gunning says an alternator typically lasts about seven years, or about 100,000 to 150,000 miles, adds Waits. Some mechanics, though, say they typically see alternators last about 80,000 miles. Several factors can affect how long an alternator lasts, including the quality of the part, conditions in which the car is driven and how many electronics are being used inside the car.
Signs your alternator is failing
In some cases, when an alternator is about to die, there are a few warning signs.
Identifying what those signs are can signal you to have it checked by a mechanic, which can save you from being stranded on the road.
Waits says one of the most common signs of a faltering alternator is when the headlights start pulsating at night, from dim to bright.
Some alternators may stop working if they are charging several electronics at once.
Other signs may include an electrical burning smell coming from the alternator, or the battery, the alternator warning light or other dashboard warning lights turning on.
A struggling alternator may also cause your car radio or other electrical components to work intermittently, or cause a squealing noise in your car’s engine.
Maintaining your alternator
Waits say there are a few maintenance tips that can prevent your alternator from suffering an early demise.
“There are a lot of things drivers can do that causes their alternator to go out,” Waits says. “People could jump start the car the wrong way, or install an accessory inside that overloads it.”
He adds that fluid leaks in the alternator or a tight belt can also cause damage to the alternator bearings, causing premature wearing.
Gunning says when the alternator goes bad, the electronics try to draw all of their power off the battery, which can cause the battery to die as well. That’s why, oftentimes, the alternator, not the battery, is the problem in the first place.
“If you see the battery light on, it’s really important to get it addressed,” he says. “If the headlights are dimming, it’s important to get a charging system test.”
Waits says the average price to replace an alternator with a remanufactured one is $400, while Gunning adds that a remanufactured alternator on a typical, domestic car, costs about $300 to $500, including parts and labor. The price of a new alternator can run from $500 to $1,000.
“It’s important to find good, quality parts,” Gunning says. “I’d go with a brand name that comes with a decent warranty.”
Most reconditioned alternators come with at least a one-year warranty, while some come with a warranty for up to three years. Some new alternators may carry a limited lifetime warranty. Check with your mechanic to learn how long the warranty is and what it covers.
