How Often Do Alternators Go Bad?

If you’re noticing that your car is having issues starting, you may be wondering just how often do alternators go bad? Alternators can usually last a long time, about 7 years or 100,000 to 150,000 miles.  But many auto mechanics report that they are replacing alternators at about 80,000 miles.  

Do you want to know just how the alternator works?  It is located on the engine, provides power to the battery, and continuously charges the battery and the car’s electrical systems and computers. The battery is to start the car, but the alternator keeps it running.  The quality of the alternator, the way in which the car is driven, and how many electronics are being used inside the car all affect how long an alternator will actually last. Unfortunately, it’s hard to know if starting issues are caused by issues with the car starter, the car battery, or the alternator.  

There are a few problems that could make the alternator go bad, such as jump-starting the car the wrong way or installing an accessory that overloads it.  Leaking fluid in the alternator or a tight belt can also cause damage to the alternator bearings, causing premature wearing.  When the alternator goes bad, the electronics try to draw all of their power from the battery, which then causes the battery to die. This is why you should inspect the alternator even if you suspect the car starter or battery may be the cause of the issue.  

Often, the alternator can go out with little or no warning.  But there are a few signs that will let you know it is about ready to die:

1. The dash warning light ("ALT" or "GEN") illuminates.
2. The lights are dimmer than normal and may pulsate from dim to bright.
3. Other electrical systems, such as power windows, power locks, dashboard lights, air conditioning, radio, GPS, etc, will start to act up.
4. Bearings in the engine may fail, creating unusual rattles. 
5. There might not be enough power in the spark plugs to start the engine, or to keep the engine alive, causing it to stall.
6. The battery will drain because the alternator is not keeping it charged.  

Remember:  Check out the alternator too if you are having starting issues before replacing the car starter or battery.

Are you wondering how often do alternators go bad?  Consult our ASE Certified Technicians at Gary’s Quality Automotive for more information about car starters, alternators, and batteries and to make an appointment.  Our auto repair shop proudly serves vehicle owners in Grand Island, NE, Wood River, NE, and Doniphan, NE.