Signs Your Alternator May be Going Bad

When you get into your car at night and need to find something in the interior, it’s nice to rely on the lights. However, if the brightness of these lights begins to wane, you could have a problem with the alternator. Because this part is connected to all electrical components in the vehicle, the interior lights may begin to suffer as the alternator starts to have problems. The dimness may vary depending on how close to dying the alternator may be. Slight dimness indicates that issues are starting, so it’s a good time to check out the alternator and consider replacing it. You may even notice dashboard lights and displays start to dim and get lighter. Headlights may also appear dim when driving at night due to a failing alternator

It’s never a good idea to ignore vehicle warning lights, even though some car owners do. Whether it’s a low oil indicator or a service engine soon light, it’s important to address these needs as soon as possible. Many cars will show a light shaped like a battery on the dashboard display or close to the speedometer. While this can sometimes indicate a battery problem, the car’s computer is telling you that the battery is not fully charged, which can also indicate alternator trouble.

Learn more about why the battery light may be on.

With some vehicles, the warning light for the alternator may be an ALT indicator. When the voltage begins to decrease, different accessories will be affected. For example, if you are using your windshield wipers and radio, power from the alternator may not be sufficient to get the headlights on too, as the alternator is already working too hard to power the other systems.

If electrical issues aren’t yet a problem, there could still be other methods for how to tell if alternator is bad. One common cause is a bad belt. Open the hood of your vehicle. If the engine belt is not on correctly or is completely missing, there’s a good chance your alternator is not going to do its job. Some belts may still be in the right spot but may be showing signs of excessive wear, looseness, or there may even be cracks. Replace the belt, and you resolve the alternator’s issues.

Car owners are used to hearing strange noises from their vehicles. Different sounds can signify a variety of potential problems. It’s no different with the alternator. Shortly before this part fails, it’s common to hear a growling or whining noise. You may not immediately recognize this sound as a clue that the alternator is going haywire, so it’s important to take the vehicle to a mechanic to investigate the source of strange noises, regardless of what the outcome may be.

Dim lights are usually an obvious clue to people that the alternator is coming to the end of its life. You may not always experience this situation. Instead, the lights may randomly flicker while you’re driving. This is a clue that the following is happening:

• The electrical system is giving out.
• The electrical system is trying to maintain the correct brightness.
• The alternator isn’t producing enough power to keep the lights going at full strength. 

Many people have experienced the frustration of finding that their car battery is dead. This ordeal can leave you stranded on the side of the road or somewhere far from home. The fact is, the battery might not be the culprit. You could have a new battery working well one day but failing the next because of the alternator. When the alternator stops working properly, the battery will try to compensate by supplying as much power as possible. The battery is able to provide enough power to start the vehicle, but it may not have enough power for long-term use. If your battery stops working, be sure to test the battery and the charging system rather than assuming other issues aren’t causing the failure.

When you open or close the windows or sunroof, or when you’re using the vehicle’s DVD player or stereo, you expect things to work quickly. If it takes longer than usual to perform these functions, the alternator could be the culprit. This would especially be the case if accessories get slower when multiple systems are used simultaneously.