Are OEM Toyota Alternators Better Than Aftermarket?

When some people are stuck with a broken alternator, they think about getting an aftermarket replacement. Is it a good idea, though? Aftermarket alternators can be cheaper, but are they worth the extra few bucks in savings?

The truth is that often times, you’ll end up paying more money for an aftermarket alternator in the long run.

What Could Go Wrong If You Install A Cheap Aftermarket Alternator In Your Car?

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Image Credit: speedkar99

Aftermarket alternators may be cheap upfront, but they can cause a lot of problems. Here are 3 reasons why you should think twice before buying an aftermarket alternator:

1. Aftermarket Alternators Can Ruin The Battery’s Ability To Hold A Charge

Some aftermarket alternators don't make as much power as they are rated to make. Under higher electrical loads, the alternator can't supply all the the power that's needed. When that's the case, the electrical components, such as the headlights, draw power from the battery. This runs the battery down more than intended. This can also ruin the battery's ability to hold a charge because it's not being fully charged.

2. Aftermarket Alternators Don’t Always Last As Long As OEM Alternators

Aftermarket manufacturers design alternators to their discretion. That means they're within their rights to build their alternators with cheap components. It's common for aftermarket alternators to come with:

  • Cheap diodes
  • Cheap bearings that will wear out faster than OEM bearings
  • Other cheap components that will cause the alternator to fail early

Some aftermarket alternators don't even work right off the bat. If you check Amazon, you'll find a lot of reviews from upset Toyota owners who bought aftermarket alternators. Here are a couple of examples:

  • "[My aftermarket alternator] fit my car just fine. It was easy to install, but it didn't work correctly. It caused the battery light to stay on. Save yourself the hassle and buy an OEM alternator."
  • "While this alternator fit my vehicle, it throws a 'check charging system' error. It was either not refurbished or made correctly, or the vehicle computer could not detect it to kick it on to charge the battery. Your money is better spent buying OEM, as this caused way too much trouble than what it's worth."

3. Aftermarket Alternators Rarely Come Under Warranty

It’s very hard to find an aftermarket alternator that comes with a good warranty. Most aftermarket manufacturers don’t offer a warranty on their alternators. Those that do are far and in between. Even so, it’s likely that their warranty policy doesn’t even cover much.

The lack of a good warranty means that if your aftermarket alternator fails, you’ll have no choice but to buy a new one. That means in the long run, you won’t save any money on aftermarket alternators.

OEM Alternators Are Built Right

OEM alternators may cost a little more than aftermarket alternators. But they deliver so much more value. Here's why:

High Quality Materials

Toyota makes a point to build its alternators with high quality materials, including:

  • Diodes
  • Bearings
  • Stator
  • Rotor
  • Voltage regulator

Because of that, OEM alternators avoid the issues aftermarket alternators have. For example, OEM alternators will fully charge the battery with the correct voltage.


OEM alternators are exactly the same as the alternator that came in your car or truck. The OEM alternator will fit perfectly, and have the exact electrical connectors needed. All the components within an OEM alternator follow OE specs to a tee. 


Toyota offers a comprehensive warranty on its parts, including alternators. The warranty is good for 12 months, and there are no mileage limitations. You can read more about the warranty here.

OEM Alternators Don’t Always Have To Be Expensive

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Many Toyota owners decide to buy aftermarket alternators, despite the risks listed above. It’s because OEM alternators can be a little expensive. What a lot of people don’t realize is that this is true only if you buy from a Toyota dealership or certain websites. They charge a hefty markup for their parts.

The good news is that you can score OEM alternators at aftermarket prices. You’ll be getting the best of both worlds. We carry genuine OEM Toyota parts at wholesale pricing. Look up your Toyota model in our catalog of alternators to see if there’s one for your car.

Written by Jason Lancaster