How Long Does It Take to Replace an Alternator? Quick Answer

The alternator is a very vital part of a car engine. An alternator of a car engine must properly work to maintain the electrical appliances of the car working. Also several times, you need to replace an alternator. And if you are curious about how long it take to replace an alternator, you can find an exact answer here. 

About 2,5 Hours! 

How Long Does It Take to Replace an Alternator?
Place of alternator in engine.

Yes, this is generally the total time to replace a car engine alternator. It may seem a very basic system but it is a very complex system that provides a very important duty in a car engine. 

This time can change according to the level of experience. If you have experience in car engine electronics, it will not take that much time to replace these systems. Some people can replace them in 1 hour. 

Also, familiarity with the car system is very important. For example, if you know all the hardware and devices of your car, replacing the alternator system will not take the time that you expected. So, it is very easy to replace them without any hesitation. 

How to Replace an Alternator? 

First of all, you need to know the general tool that you need to replace these systems. And if you have these tools you can start to replace the alternator system that your car has. 

Tools You Need 

  • First, of all, you need to buy the same alternator that your car uses. You need to check the type label to buy the same alternator for your car engine. Also, there are alternatives in the aftermarket that you can choose for lower prices. But aftermarket parts will not provide the performance that the OEM part produces. 
  • Belt tensioner: Belt tensioners are located at the belt system of the carç They are small pulleys that you can adjust the tension of the belt. 
Belt tensioner.
Belt tensioner.
  • Toolbox: You need to use basic hand tools that your car needs every time. Spare fasteners, screwdrivers, wrenches, pliers, and other basic and main tools will be required while you are changing the alternator of your car. 
  • Voltmeter: It is also very important to test the voltage output of the alternator system that you attached. If it does not provide the required amount of voltage while the car is running, you need to check other important things. 
  • Replacement serpentine belt: If you need to replace the belt system of the old alternator, you need to check the available belts. You need to be sure that the belt system is compatible with your car. 
  • Rags: You will need to clean the parts that you detached from the engine. Working with oily pğarts is not safe and easy. 
  • Gloves: Be sure that you have safety gloves that protect your hand from cuts and scratches. 
  • Safety glasses: Always wear safety glasses to protect your eyes from the objects that can jump from the system that you are dealing with.

Steps to Change Alternator

You can follow these steps if you want to change the alternator of your engine. 

  • First of all, you need to save the late memory of your car if you have the latest brain system. It is very important to run your car with the latest software after the replacement. 
  • After that, you need to disconnect the negative battery cable from the battery. Because you do not want to deal with electrical things when the battery is connected to the electricity system of your car. Think about how you are dealing with electrical installments in your apartment. What you need to do is, cut the electricity of your apartment before dealing with terms of safety. 
Negative side of battery.
Negative side of battery.
  • You can start to remove the old alternator that your car has. The alternator is directly connected to the belt system of your car. And this belt system is very tense. You need to loosen the belt tensioner of your car. There will be a small wheel that you can adjust the tension of the belt from that pulley. By taking that pulley, you can easily adjust the tension of the belt without any problem. 
  • The alternator is a part of the charging system of the battery of your car. So, it is connected to the battery. When the engine is running, the alternator pulley runs the alternator bobbin to create voltage to charge the battery. You can understand that there are wiring connections between the battery and the alternator. You need to disconnect these wiring connections. And know or note the connection places and edges of the cable to make the same connection while you are attaching the new alternator to your car. 
Cable connections on alternator.
Cable connections on alternator.
  • In this step, you can remove the alternator system from the attachments to the engşine block. It is probably attached with different fasteners to the engine block. Disconnect these fasteners and detach the alternator from the block. 
  • Prepare the new alternator that you will attach to the engine. And place the new alternator to place of the old alternator. Be sure that you put in the same orientation. 
  • Attach the fasteners and other elements to the holes to attach the new alternator. Tighten the fasteners by using the torsion wrenches and make sure that you fit the system properly to your car. 
  • After that, you can attach the cables and connections in the same orientation that you attached to the system. You need to be sure that you attached it correctly. If the alternator does not work properly, your battery will drain. 
  • Attach the belt to the alternator and adjust the tension of the belt from the belt tensişoner. The best tension for your belt is, when your push with your finger to the belt, it must bulge only 1 cm. You can assess the tension of the belt like this. 
  • You can connect the negative side of the battery after the installment. 
  • You need to test your alternator with the voltmeter. You just need to place the sticks of the multimeter to the battery voltage while the engine is running. The voltage must be between 13.8 and 14.2 volts. This means, your alternator is successfully installed. 

How to Understand Bad Alternator? 

Alternator cable connections of battery.
Alternator cable connections of battery.

The alternator is a very important vital part of the car electrics. Because it provides the required electricity to car electric parts such as car lights, radios, and spark plıugs. So, it is very important to have a good working alternator in your car. There are different kinds of assessments that you can make for your car and understand that you have a bad alternator to change. 

  • The first important thing that you need to pay attention to is the dimming lights. This means the alternator that you have do not work well. And it can not provide the electricity that your car’s electrical components need. When you increase the rev of the engine, the lights become brighter. This means you have a problem with your alternator. 
  • You can have a problem with your radio and the speakers do not work properly. And you can not control the radio. 
  • As we explained above the alternator system is directly connected to the belt system. So, the belt system must properly work. And if there is grinding down that comes from the belt system, you can understand that the belt connections are not good. Also, there can be problems with the pulley systems that the alternator connects. 
  • Engine shut-off is also a very common problem while you are driving your car. Because the electrical system of your car can not provide the required electricity for your engine. 
  • The battery warning light will also flicker if you have a problem with your battery light. So you can be sure that you have a problem with the alternator system of your car. 

Maintenance of Alternator 

Like the other parts of the engine, you need to change the alternator of your engine in specific periods. But if you make regular maintenance, you will not have any problems for much longer periods. 

You need to bring your vehicle to the regular maintenance periods to mechanics. If you have any problems, experts will warn you about the parts of your car. And they will provide the information about what they changed and what you need to make to maintain the critical components of your engine. 

Also selecting the correct belt application is very important. Always consider OEM parts for your car. Probably, OEM parts are higher in price if we compare them with the aftermarket ones. But you will not need to change them frequently kike the aftermarket parts. 

Probably need to change the belt between 60.000-100.000 miles. 

Be sure that the alignment of the alternator is well in your engine. If the alignment is not good, you will have problems in very easy periods. To prevent it, you need to adjust the alignment of your belt properly. 

Also cleaning all the grime and debris from the alternator is very important. Because it is very important to take fresh air inside the structure of the alternator. And if there is a lot o grime and debris on the alternator, you can face problems in the future. Always be sure that your engine is clean enough. 

What are the Prices of Alternators? 

The alternators themselves will not be a big money. If you have an average car like Toyota or Honda, the prices will range between $50-$100 for OEM parts. 

But the labor cost for the replacement would take money from you. Because as you see above, it is a very laborious process and takes lots of time. Because of it, the replacement costs of the alternators can range between $350-$700. 

If you manage to replace it yourself, you will not have any problem paying that money. 

But if you are not familiar with car mechanics, it is very important to leave this job to experts. 

General Lifespan of Alternators 

In general, you can use an alternator in your car for 5-7 years. And in terms o mileage, it will take around 50.000 miles for your car. Furthermore, if you make the maintenance correctly on your system you can use them for much higher years. 

Last Words on How Long Does It Take to Replace an Alternator 

As you see above, we explained all the important details about alternators. And you know how much time you need to spend to replace the alternator system of your car. 

It takes around 2 hours because these systems are connected to other systems of your car. You need to detach lots of things to replace them. 

If you have additional comments and questions about this topic, please leave them below. 

Related articles; 

How Long to Let Engine Cool Before Adding Oil? EXPLAINED!

Temporary Fix for Bad O2 Sensor – Detailed Guide

Ceramic Seal for Paint Protection of Your Car

Battery Acid Neutralizer – Why and How to Use?


How long does it take for a mechanic to change an alternator? 

If you know the car and are experienced with the model, it will take around 1.5 hours. But if you are not familiar with the model of the car that you are dealign with, it will take much more time such as 2.5 hours. Because you will probably not be sure about the place of the fasteners and electrical attachments. 

Is it easy to change an alternator? 

It is not easy to change it. Because it is connected to other systems in your engine. And you need to detach these connections to replace them. But if you are experienced or familiar with car mechanics, you do not need to use some sort of special tool to replace it. You can do it with your toolbox easily without any problem. 

How quickly can an alternator fail? 

It depends on the way of using your car. It can fail very quickly if you do not make the important maintenance. And the lifespan can be high if you consider the maintenance and make regular applications. 

Can I drive my car with a dead alternator? 

Staring at the cart without an alternator will be hard. And also working the electrical systems with the battery itself is risky. The answer is yes you can. But the battery will drain quickly. But if you need to run your car, you need to bring your car to a car electric expert immediately to take care of the situation. 


How to replace an alternator? –

How much does it cost to replace an alternator? – Napa Blog

Alternator – Wikipedia

How does an alternator work? –

Uğur Uygun

Hello everyone, I am Uğur. I am a mechanical engineer who has experience in different R&D departments of HVAC companies. With my best friend, I decided to build this website to share out knowledge and experience. And also, I am interested in automotive. So, I am writing about automotive and automotive-related articles here. Sharing my knowledge and experiences on these topics is a very big pleasure for me. I am willing to answer all of the questions people have about these topics.

Related Articles

Leave a Reply

Your email address will not be published. Required fields are marked *

This site uses Akismet to reduce spam. Learn how your comment data is processed.

Back to top button