How Long Does It Take To Replace An Alternator?

How Long Does It Take To Replace An Alternator?


April 18, 2022

If you are a beginner and looking for the answer to “how long does it take to replace an alternator?” Keep reading!

The car battery is often the first thing that comes to mind when people think about an automobile’s electrical power. The battery, on the other hand, generates the least amount of energy for a vehicle.

The alternator is responsible for supplying your automobile’s major accessories and electrical components.

In this post, we’ll explain what an alternator is and how long it takes to replace one, as well as how to tell whether or not your current one isn’t working.

What Is an Alternator, and Why Does it Matter?

What Is an Alternator, and Why Does it Matter?

When you start your car, the battery provides enough electricity for the ignition to operate. The battery then serves as an electrical reserve only in case of an alternator fault. In general, a car’s alternator is the “king” of its power supply.

The alternator is the part of an automobile’s electrical system that converts the internal combustion engine’s mechanical energy into electrical energy. The electricity generated by the alternator powers the vehicles’ electronics.

The alternator, which is linked to the car’s engine, is a generator that converts mechanical energy into electrical energy by converting rotational force into electricity. You should think of it as an electric motor in reverse when you think about the system.

The battery merely provides the electricity necessary for the electric starter to fire up your car. After the key is turned, your alternator begins to produce power for all of the systems that require it. It also prevents the battery from being completely drained by charging it while the car is in motion.

How Long Does it Take to Replace An Alternator?

How Long Does it Take to Replace An Alternator?

A seasoned expert mechanic should be able to replace your alternator in roughly 2 hours depending on the make and model of your car. Most businesses in the United States, however, will charge you for a full working day.

If you decide to change it yourself at home without any prior knowledge, it will take about 3-4 hours for your car’s make and model. Please do not try to replace your alternator yourself if you have no mechanical expertise; you may damage your vehicle or yourself while working with electricity.

How Long Do Alternators Last?

How Long Do Alternators Last?

Alternators live longer than automobile batteries. Automakers, on the other hand, give varied estimates when asked about the life of an alternator. The average lifespan of a car’s alternator is 4 to 7 years, however, that depends largely on how often you drive it.

Between 40,000 and 80,000 miles, almost every car requires an alternator replacement. As a result, if we’re talking about a new vehicle with no mileage on it yet, it’s unlikely to have problems until after 80,000 miles.

Is It Possible To Check Whether Your Alternator Is Bad Without Taking The Car Into A Repair Shop?

Is It Possible To Check Whether Your Alternator Is Bad Without Taking The Car Into A Repair Shop?

The alternator is a tiny but crucial component that powers all of your car’s electrical systems and accessories. Electrical accessories may fail if the device fails, and the vehicle may even be entirely disabled.

Flickering Lights/Dimming

Flickering lights on the instrument panel are one of the early indications that your alternator is failing. If your headlights dim and flicker when idling, but brighten as the engine speed rises, your alternator is not working.

The instrument cluster may not work, or it may be unresponsive. The radio or climate controls, for example, could fail to function. A faulty alternator might cause any number of issues with your vehicle’s electronics.

Grinding Sounds

The alternator in your car spins a rotor that generates a constant, changing electric current. If it’s damaged, uncleaned, or un-lubricated, this might cause friction within the alternator to grow.

Because it uses an inherently inefficient process, an aluminum smelter would have to work much harder than one using a traditional thermal power plant.

In addition, the shattered surface may produce grinding noises throughout the procedure, which you may hear when operating.

Sliding Belt and Corrosion-Resistant Pulleys

The alternator’s rotor absorbs the energy produced by the engine. A belt turns as the motor spins. In most vehicles, this belt also drives the steering hydraulic pump and air conditioning systems in addition to the alternator.

The alternator, which is mounted beneath the crankshaft, may get damaged by this belt or pulley. However, there could be a variety of other causes for belt and pulley issues.

If you have a problem with your automobile’s hood, there are certain things to check. Any garage you take the car to will do a more thorough examination of all belt accessories within the hood to identify the issue.

Turning Off While Driving

This is a serious electrical problem caused by a faulty alternator if all the lights and accessories in your automobile begin to go out on their own and the car dies on the road while you’re driving.

If the alternator isn’t charging the battery properly, it will discharge until there is nothing left in the system. Then the automobile will not start up again because the battery does not have enough energy for the starter motor.

You’ll need to search for a rapid charging method in this case. If you’re unable to charge your phone at all, check out the FAQ area below to see what you can do if that happens to you.

What Equipment You Need to Replace an Alternator

What Equipment You Need to Replace an Alternator

For the most part, you can replace the component without using any special tools, depending on whether your car has a serpentine belt. You’ll need:

  • Socket wrenches
  • Open-end wrenches
  • Belt tensioner (if necessary)
  • Voltmeter
  • Replacement part
  • Pry bar or large screwdriver (optional)
  • Memory saver (optional)
  • Work gloves

The final item is a deal-breaker. You won’t need to scan used car values or new automobile pricing, but it may be costly depending on the model. The component will set you back at least $200 in most cases.

The belt tensioner will cost $50 to $100. This is true, but it will cost you more in labor than the alternator does.

The expense of taking it to a mechanic varies depending on the manufacturer and model. The expense of repairing an older Ford vehicle might range between $300 and $400. A more recent foreign SUV will cost considerably more, possibly reaching as high as $1,000.

It’s a medium-level project. You must have some experience working on automobiles. If you know anything about automobiles, it’ll only take you an hour or so to complete the task. It all depends on what needs to be done to get the old one out.

As with any repair, you should double-check everything while you have the opportunity. You should check any belts for wear.

How To Replace An Alternator

How To Replace An Alternator

Before you begin, check the battery and alternator to see whether they need to be charged and if the problem is with one of these components.

You can expect a reading of around 12.5 volts for the first with the automobile off and about 14 volts when started if everything is all right. Then, using your voltmeter, measure the voltage after some accessories are running, such as your headlights.

If it stays the same or rises, you’ve got a problem that must be addressed immediately. If the battery is under 50 percent charge, you’ll need to restore it to full before beginning the repair. You should use a memory saver for your newer car, as well. You only have to reset the clock on older models.

Before you start working on your automobile, do yourself a favor and double-check the belt. V-belts were used in older vehicles, whereas serpentine belts are used in more recent models.

Examine it for fracture lines and wear. If it appears to be a piece of junk, grab one from the parts store when you replace the alternator so you don’t have to make another trip.

Also, check for corrosion in the battery. Clean the posts with a towel. There are also materials available that will prevent it from happening. Felt disks may be used to cover the post as well. Also, look for any signs of wear on the cables.

Over time, the rubber case will dry out. It’s simple to replace new ones. And you may buy them for less than $20.

Turning Off The Battery Power

The next step is to remove the battery. Metal tools in your hands and a live electrical connection don’t mix well. You may also do more harm and increase your costs by doing so. It is sufficient to remove the negative cable.

You don’t have to remove either of them. Breaking the current with one removal would be dangerous. It only takes a milliamp of electricity for you to feel it.

Removing The Alternator

Remove the alternator’s power cable first by using a socket or an open-ended wrench to remove the bolt. After that, unplug the harness. It’s now time to loosen the belt. It is once again dependent on the car. It is possible that the mounting hardware simply needs to be unscrewed or the belt tensioner tool used. If you detect the damage, you’ll also need to pull out the belt.

Be cautious while removing a serpentine belt. The word “tension” is particularly important here. Don’t allow it to snap back and strike you or harm any other components underneath the bonnet. You can remove the belt and continue with the job once it’s free.

After you’ve completed these steps, you may remove the old alternator from its casing. Take a minute to compare the new and old ones to ensure you have the correct part. Look at how the holes line up and where the connections are. After all, things go wrong from time to time.

The New Is Meant to Replace the Old

It should be simple to insert the new alternator. Keep any wires away from the prongs. Make sure you don’t pinch anything. It shouldn’t be pushed in too far. If you replaced a belt, now is the time to do it.

Then, tighten the bolts. If no pulley is applying tension to the belt, you can pry it loose with a pry bar. The Goldilocks zone is one where there’s enough play but not too much. It’s about one-half inch of swing that’s ideal.

Next, install the new alternator’s harness and power cable in the reverse order you removed the old one. Check for any loose bolts and ensure that nothing remains inside the engine compartment.

Connect The Battery, Then Test The Job

Now is the time to see whether you’ve done it correctly. First, reattach the negative cable to the battery. Make sure both of them are tight. Turn on your car and check the voltmeter while it’s running.

If everything is fine, it will read 13.5 on the next occasion (after your initial start-up). You’ve followed all of the steps in the correct order. The next stage is to follow up to make any necessary modifications.

After a few days of driving the car, check the belt’s tension to ensure that it’s still in the correct place. Then give yourself a pat on the back for a job well done and a sigh of relief that you won’t have to go shopping for another automobile on Car Finder.

Don’t forget to reset the vehicle presets using the memory saver, as directed by the device.

When deciding how long it takes to replace an alternator, the most important thing to consider is that it’s a chance. You’ll be able to inspect other components beneath the hood and save yourself time and trouble on the road.

Although it is a repair, it is also preventative maintenance for other components that may fail and leave you stranded.



Jeffrey Bryce is an experienced motorcycle rider with years of experience caring for motorcycles. His natural fondness for motorcycles have made him come up with, which is dedicated to answering and teaching you how to care for your bike with the care it requires. LetsGoForARide is the one of his important lifework in reaching out to communities of motorcycle enthusiasts on how to take care of their bike and choosing the correct spare part.