4 Common Signs Of A Failing Alternator

26 July 2017
 Categories: , Blog


Most car owners don't spend much time thinking about their vehicle's alternator. But an alternator plays an important role in continually recharging the car battery, while also powering the starter, ignition, and electrical components. When an alternator completely fails, the car will not operate properly. It is in your best interest to know the signs of a failing alternator so you can have it replaced promptly. Some of the common signs that an alternator will need to be replaced very soon include:

Dimming Lights

When an alternator is failing, it is very common for lights to dim inside the car. This can include overhead lights, dash lights, and lights on the radio. In many cases, the headlights will also be much dimmer than usually when the alternator is no longer working properly. In addition to dimming lights, you may notice that electrical components in your vehicle, such as power seats and power windows either move very slowly or stop working all together.

Bad Battery

In many cases, a failing alternator can have similar symptoms to a bad battery. So people replace the battery and think that the problem is fixed. But if your alternator is going bad, a new battery will not last for long because the alternator will not be able to recharge it while the vehicle is turned on. If your battery is relatively new but it is very weak or completely dead, there is a very good chance that you need to replace your alternator.

Strange Sounds

Any time you hear strange sounds while operating your vehicle, there is cause for concern. A bad alternator can start making strange sounds as the components inside the part begin breaking down. When bearings inside the alternator break or wear out, the can produce a whining or grinding sound when the vehicle is in use. 

Warning Light

Many modern vehicles are designed with a warning light on the dash to warn you when the car's computer notices that the alternator is failing. In some cars the warning light may say "ALT", but in many vehicles the warning light will look like a battery, which can be confusing. If the battery light illuminates on your dashboard, don't automatically assume that the problem is your battery. Instead, take your vehicle to an auto repair shop where a mechanic can test both your battery and your alternator to determine which one is in need of replacement. 

If you notice any of the above signs, have your car checked out by a professional at shops like Oak Hollow Tire Car Care Center Inc.