How often should an alternator be replaced?

An alternator usually lasts between 80,000 to 150,000 miles or 7 to 10 years, depending on the vehicle and driving style. However, there's no fixed replacement schedule like with oil changes or filters. Instead, alternators should be replaced based on their condition and performance.

Signs your alternator might need replacement include:

• Dim or flickering lights: Your headlights or dashboard lights may flicker or dim.
• Battery warning light: The battery light on your dashboard illuminates, signaling charging problems.
• Electrical failures: Malfunctions in power windows, radio, or other electronic parts.
• Weak or dead battery: A failing alternator might not correctly charge the battery, causing it to weaken or die.
• Strange noises: Grinding sounds may indicate alternator-bearing problems.

To avoid unexpected alternator failure, regular checkups during routine maintenance are key.

Wondering how often should an alternator be replaced? Call our ASE Certified Mechanics at Clausen Automotive, The Hybrid Shop, for more information about starters, alternators, and car batteries and to request an appointment. Since 1975, our family-owned auto repair shop has proudly served vehicle owners in Madison, WI, and the surrounding communities.

What Causes Alternators to go Bad?

Are you starting to experience starting issues and don’t trust your car anymore?  Is there an issue with the battery, the alternator, or the starter, you wonder? How do you know which one?  

What about the Starter System?

The alternator is located on the engine and provides power to the battery, continuously charging it along with the electrical system and computers.  The battery ignites the starter, but the alternator keeps the car running.  The lifespan of an alternator is affected by the quality, how the car is driven, and how many electronic accessories are being used inside the car.   When you start having starting issues though, it’s difficult to know whether it’s the fault of the car starter, the car battery, or the alternator.

Even though the starter system was designed for repeated use under a variety of weather and road conditions, just the usual wear and tear, extreme conditions, and poor maintenance can all create issues.

What Causes Alternators to go bad?

• Using jumper cables wrong, 
• An accessory that overloads the charging system,
• Leaking fluid in the alternator, or
• A tight belt in the alternator that can damage bearings.

When the alternator goes bad, the battery will ultimately die as the electronics have to draw all of their power from it.  Inspect the alternator even if you suspect the car starter or battery may be the cause of the issue.  The alternator can die with little or no warning but there a several signs to watch for:

1. The "ALT" or "GEN" light illuminates on the instrument panel.
2. The lights are dimmer than normal and may pulsate from dim to bright.
3. Other electrical systems, such as power windows, power locks, air conditioning, radio, GPS, etc., will start to act up.
4. Bearings in the engine may fail, creating unusual rattles. 
5. The engine will stall as there is not sufficient power in the spark plugs to start the engine or to keep it running.
6. The battery will lose its charge because the alternator can’t keep it charged.  

Remember:  If you are having starting issues, before replacing the starter or battery, check out the alternator. It could be the culprit!

Are you wondering what causes alternators to go bad?  Call our ASE Certified Technicians at Clausen Automotive, The Hybrid Shop, for more information about your car starter, battery, and alternator and to make an appointment. Since 1975, our family-owned auto repair shop has proudly served vehicle owners in Madison, WI, and the surrounding communities.