How Long Does An Alternator Last? Read to Find Out

Have you ever wondered about the role of alternators in your vehicle? Contrary to some people’s misbelief, they hold a more important role than expected.

Without alternators, the electrical system can’t generate direct current to serve as a power source for other sections, pitching your car against many performance issues.

That’s why you should know about its service life for timely replacement.

How long does an alternator last? How should drivers maintain and clean them? Are there any extra tips you happen to overlook?

This article from Bryan’s Garage will address all these inquiries. Keep scrolling!

How Long Does An Alternator Last?

How Long Does An Alternator Last?

How long does a alternator last? Generally, you should expect a common alternator to last from 40,000 to 100,000 miles, equating to seven or eight years.

Nevertheless, be prepared that these estimations might fluctuate (slightly or drastically) due to numerous factors.

After all, your car is vulnerable to many external variables that not many experts can predict.

Let’s take the rotor spins on your alternators as an example.

Though these compartments are expected to last a lifetime, we all know that such a scenario is impossible: natural tear and wear, buildups of grime and dirt, and (sometimes) unexpected crashes can damper their performances much sooner than you would like.

Other equally vulnerable parts, such as the voltage regulator, also contribute to the alternators’ shortened lifespan.

And do not forget the excessive gas engine, either – particularly in cars that often engage in long-hour trips! 

So what’s the main takeaway here? In short, while you might not have to worry about replacing them for at least a few years, remember that the following variables decide how long alternator last:

  • The alternator output quality
  • The power drain
  • Driving conditions (dangerous conditions shorten its lifespan)

It would help if you also looked for some simple common symptoms of failing alternators, which include:

  • GEN or ALT lights are on
  • Dimming dashboard light
  • Dimming headlight
  • Power loss during idling sessions

We will return to this issue in the latter half of the article, where more severe red flags will be in the discussion regarding how long do alternator last.

How Should You Clean and Maintain Your Alternators to Lengthen Their Lifespan?

Now that you already know an alternator last how long, it’s time to learn all the important maintenance strategies to strengthen their performances.

Step 1. Pick Suitable Cleaners for The Task

Most auto stores have numerous cleaner options available, so it’s not difficult to choose one of your preferences.

Our pick is the CRC or AutoZone alternator cleaners, which are quite helpful for scrubbing electrical windings.

Not to mention, their strong formulation ensures no grime and dirt can get accumulated. Sounds amazing, right? 

Step 2. Detach Your Alternators

Open the hood of your car to detach its alternators. Once done, place the device – and your cleaner and brush – on a work table, ready for the next steps ahead.

Step 3. Dilute The Degreaser

Already have a degreaser with you? Good! Now mix the cleaner and water in a 1:1 ratio.

Do not worry that this ratio seems lacking; many of our experiments have proven that it’s more than enough to pull all specks of dirt out.

Step 4. Apply The Mixture

Soak the cleaner on your alternators using a cloth. Another method (equally effective) is to purchase spray bottles containing the cleaners and spray their content gently.

After that, let your cleaner be absorbed for some time, which softens the grime and pushes it out faster.

Step 5. Brush Slightly

Pick a brush (as soft as possible) to tackle all areas that still look soiled. This action would help you attack and get rid of all the remaining accumulated dirt.

We also recommend concentrating on the connection terminal points, which are usually the dirtiest.

Step 6. Flush

Rinse everything gently with water. Leave the alternators to dry on their own, keeping damages and rust at bay.

During the process, you might have missed some dirty electric connections. Double-check them one last time and clean them again if necessary.

After this is done, it’s safe to say no electrical components in your alternators will suffer from damage.

Extra: Things to Avoid

Refrain from doing the following if you are concerned about how long do alternators last:

  • After deciding what cleaner to spray, you must ensure none is spread directly on the inlet openings.
  • Though they are not always dangerous, it would help if you sidestepped degreasers with petroleum bases altogether.
  • Lastly, do not use compressed air or pressure washing. These methods might hamper the alternator quality.

Common Red Flags You Should Not Ignore If You Want Your Alternators To Last Longer

Common Red Flags You Should Not Ignore If You Want Your Alternators To Last Longer

Weak or Dead Battery

Alternator battery cables going dead are one of the most common red flags. To check that, you can jumpstart the vehicles via the jumper cables.

If the car dies right after these jumper wires are removed, the entire alternator itself is failing. And if it still runs? Then the bad batteries are the culprit here.

Grinding Noises

When some vital components start wearing down (ex: needle bearings, rotors, or stators), they will produce screeching, strange noises that don’t seem like how your car usually sounds.

Trust your instincts and take it to an alternator repair shop or professional mechanic.

Low-Powered Electric Components

Do you notice the lights get dimmer or keep flickering? That’s a clear indicator of a bad alternator failure.

Other low-power signals include slow-moving wipers/power windows, inconsistent radio sounds, or blinking battery warning lights.

In short, any telltale signs of the vehicle’s struggle to generate power are considered alarming.

Foul Smell

Do you spot a smell similar to burning rubbers – even if you have just bought the car? 

That’s because your serpentine belts have slipped on the alternators’ pulleys, causing heated seats and a terrible smell akin to electrical fires.

It’s time to investigate the issue and tighten the drive belt! 


How long does an alternator last? This insightful article from Bryan’s Garage has explored the issue in depth, accompanied by numerous extra pieces of advice to guarantee a high-performance alternator for your precious cars.

Keep them in mind all the time, and pay close attention to all unusual warning signs and red flags in order to give them on-time treatment.

Most importantly, try your best to keep a consistent cleaning schedule for your alternator terminals – at least once or twice a week.

Have a maintenance service do that for you if you don’t have time. But regardless of your choice, never leave these devices neglected for too long!

Still have questions or confusion about how long does alternator last?

You are welcome to contact Bryan’s support team for more help on common alternator issues.

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