What Is A Car Alternator? Learn About Cost, Location, Replacing etc.

The car alternator is a vital part of the car that helps power the smaller electronic devices.

Let me explain what it is, where it is, and what it does.

What Is The Alternator On A Car?

The alternator is a generator that works with your car’s battery to power all electrical gadgets (like your interior and exterior lights, instrument panel, and power windows). It runs while your car’s engine is on, dutifully keeping your battery charged and ensuring your car’s electrical system remains powered.

Every car with a standard internal combustion engine has an alternator.

It harnesses the power of alternating current (AC), hence the name “alternator.” When your engine is running, a belt driven by the crankshaft spins the alternator, generating electricity. This electricity is then used to power all those gadgets we mentioned and, most importantly, recharge your car battery.

What Does An Alternator Look Like?

The alternator is the size of a coconut with lots of vents on its aluminum body. These vents help the alternator stay cool. One end features a pulley that’s part of a rubber belt system. As the engine turns, the belt also spins, allowing the alternator to do its job.

Car alternator explained

Inside the alternator, there’s a large cylinder with triangular finger poles around the circumference.

This is the rotor.

The rotor houses a series of alternating finger pole pieces placed around coil wires called field windings, which wrap around an iron core on the rotor shaft.

Do All Cars Have An Alternator?

Except for some hybrid models, all vehicles with a standard internal combustion engine will have an alternator.

Electric cars do generally not have an alternator.

Where Is The Alternator Located?

The alternator is typically located near the front of your engine.

Accessing the alternator can be relatively straightforward or a bit more complicated, depending on your car’s make and model. In some vehicles, the alternator is easily accessible from the top. In others, you might need to remove some components, like the airbox or even the radiator, to gain proper access. Make sure to consult your vehicle’s manual or a trusted mechanic if you’re unsure about what needs to be removed.

How Long Does An Alternator Last?

An alternator lasts anywhere from 40,000 to 100,000 miles. Sometimes, you’ll find that an alternator can reach a whopping 200,000 miles or even more. On average, alternators last about 7 years or 150,000 miles, whichever comes first.

While driving, you might start noticing signs that your alternator is wearing out. Keep an eye out for stuff like power loss to accessories when your car is idling, dimming headlights, or dimming dashboard lights. If you see the ALT or GEN light flashing on your dashboard, that’s a pretty clear sign that your alternator might be worn.

Remember, an alternator’s lifespan ultimately depends on factors like the quality of the part and the amount of work it has to do.

How Much Do Alternators Cost?

A new alternator costs between $130 to $600, depending on your vehicle’s make and model. That’s quite a range!

Now, if you’re on a tight budget and considering a used alternator from a scrap yard. Make sure to do a bit of research to find the best deal.

For a better idea, here’s a table showing both new and used alternator prices:

Condition Price Range
New $130 – $600
Scrap Yard $20 – $100

How Much Does It Cost To Replace An Alternator?

You should expect to pay $150 – $400 to get an alternator replaced. Some shops charge flat rates for specific repairs, while others have hourly rates that can range from $50 to over $100 per hour. Keep in mind that replacing an alternator typically takes 1-3 hours, so that should give you a ballpark idea of the labor cost.

What Happens When An Alternator Breaks?

When your alternator is worn, one common problem you might notice is dim or flickering lights. This is usually most obvious with the headlights, but you might also see it in the dash lights and dome light.

If you discover that your lights get brighter as your engine RPMs pick up, that’s an even better indication of an alternator issue.

Another sign of a failing alternator is a warning light on your dashboard.

If your alternator’s output goes below or above a set limit, then your car’s warning light will come on. In most vehicles, this light looks like a battery.

In addition to these symptoms, a broken alternator can lead to other issues like strange noises or smells, slow accessories, and even regular stalling or difficulty starting your car.

Your vehicle relies heavily on its electrical system, so problems with your alternator can quickly impact your ability to drive safely.

Can you continue driving with a faulty alternator?

Technically, you might be able to keep going for a short distance if your battery has enough charge left. However, it’s really not a good idea to keep driving without a functioning alternator, as it can lead to further damage or leave you stranded with a dead battery.

If you suspect your alternator is failing, it’s best to get it checked out and repaired as soon as possible to prevent further complications.

Can You Replace An Alternator Yourself?

Yes, you can replace an alternator in a car yourself.

First, gather the necessary tools and materials. Typically, you’ll need:

  • a socket set,
  • wrenches,
  • gloves,
  • and a new alternator.

It’s also a good idea to grab a voltmeter to test the old alternator before you begin.

Next, disconnect the negative battery cable and use a memory saver to save your vehicle’s electronic information.


Examine the belt connected to the alternator—it could be a serpentine belt or a V-belt. To remove the old alternator, you’ll need to loosen the tension on the belt.

Once you have access to the old alternator, disconnect any electrical connections and remove any fasteners holding it in place. Carefully take the old alternator out of your car and compare it with the new one to make sure they’re identical.

Install the new alternator by following the steps above in reverse order.

  • Attach the alternator to the engine,
  • connect the electrical wires,
  • and then adjust the belt tension.
  • Finally, reconnect the negative battery cable
  • and start your car to test the new alternator.

If the battery is charging correctly and there are no warning lights on the dashboard, then congratulations—you’ve successfully replaced your alternator!

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