How Long Does it Take to Replace An Alternator?

Published: 09/14/22 •  7 min read

You need to look into two main reasons your vehicle has an electrical problem—the alternator and battery. Suppose your car’s battery is working well, then the alternator may be the cause of the problem. After testing the alternator and finding that it is a problem, you will need to replace it. An alternator replacement can take around two hours when done by a mechanic, but it could take more time if you do the job yourself or are new to this type of repair.

How Long Does it Take to Replace An Alternator?

It’s a frequent question that has a simple answer. The model and make of the vehicle you own will decide how long it will take to change an alternator. However, typically, one to two hours are sufficient. Other factors that influence the amount of time required for replacing the alternator include access to the alternator to a specific vehicle and particular ordered parts.

What Is an Alternator?

How Long Does it Take to Replace An Alternator
Car Alternator

When we start our car, the battery produces the required electrical charge to ignite. Following that, the battery serves only as an electric reserve in the event of an issue in the engine. 

The alternator is considered the ‘king’ of the power supply for a car.

It converts mechanical energy generated from the combustion in the engine’s internal components to electrical energy. So, the electrical energy that powers the automobile’s electronics is generated by the alternator.

It transforms the mechanical energy into electric energy through the force of rotation generated by the engine. The battery just provides the power needed by the electric starter. Once the ignition is turned on, the alternator generates energy for all the systems that require it. It also helps prevent the battery from becoming exhausted by charging it continuously while the vehicle is moving.

How to Know That Alternator Needs Replacement?

Let us now discuss various signs representing that the car alternator needs repair or replacement. 

Faulty Electrical devices

If an alternator fails to function, electrical devices may stop working, and your car could get disabled completely. If you have problems with the electronics in your car, like climate control or radio, it indicates a faulty alternator.

Dimming Lights

Since the alternator provides electric power to your car, one of the most alarming indications is flickering illuminations on the dashboard. If the headlights of your car flicker and dim, become more bright as you speed up the engine, it is an indication of an alternator being under-performing and needing replacement. 

Shutting Off of lights While Driving

When all lights and other accessories of your car turn off by themselves or stop working while driving, it is an electrical issue that can be traced to a defective alternator.

If the alternator is not functioning correctly, the battery will deplete. The car stops and won’t start again since the battery does not contain the required power. We recommend looking for a fast-charging alternative. 

Grinding Sounds

The alternator produces a constant and alternating electric current. If it is not adequately lubricated or damaged, it can create more friction within the alternator. It will therefore have to work harder to produce electricity. Additionally, the damaged surface could result in grinding noises.

Sliding Belt / Damaged Pulleys

The rotor inside the alternator draws energy generated by the motor. When the motor spins, it turns the belt. The belt drives the hydraulic pump for steering and A/C, in addition to the alternator. The problems with this belt or pulley of the alternator could also be the reason. Make sure to perform an extensive examination of the belt and its components in order to figure the issue.

Red Warning Light

A red warning light on your car’s panel indicates discharged batteries, which could be due to an alternator issue. The alternator and the battery are connected directly

. The alternator helps keep the battery and engine in good condition. 

How to Replace an Alternator?

When you repair the alternator, you will likely be dealing with electricity. It’s not a complicated procedure, but you will require some knowledge of vehicles if you plan to tackle it independently. So it is better to get assistance from a professional.

Here we have come up with the step-by-step instructions. Be sure to read the manufacturer instructions based on the model and make of your vehicle. You may also need to replace parts of the particular model, including an alternator, battery, belts, tensioner cables, and bolts.

Prep Work

To begin with, in the process of replacing the alternator, take off your cord for the battery at the positive end and find the alternator in the engine compartment. If it is closer to the ground, and you cannot access it from the top, ensure to park the car on level ground and lift it. Be sure to pull your handbrake before putting your vehicle on jack stands. 

Remove the Alternator

Utilize a socket wrench to let the belt loosen by shifting the alternator’s pulley. Then, remove the bolts that hold the alternator. Depending on the design of the bolt as well as the method of removal, it will take about 2 to 4 minutes. You can utilize socket wrenches to take off the bolts and hold the alternator. Make sure to remove the alternator only after completely removing the nuts by disconnecting the electrical connection. 

Set Up A New Alternator

Make sure to test the new alternator against the original one. Check that the voltage and pulley are the same as the previous one. If not, change the alternator to the compatible one.

You will need to reverse the procedure to set up the new alternator. Connect the electrical wires and plugs into the alternator’s new circuit. Then slide it into place, and attach the bolts. When attaching the bolts, replace the alternator pulley, and make sure that the belt is correctly aligned. You can use a socket wrench to obtain the amount of slack needed and place the belt over the alternator’s pulley. After that, release the pulley to ensure that the belt is in the proper tension.

Now, reconnect the battery cable to the positive terminal. After that, start your vehicle and check. Make sure your alternator is charged with a battery.

Frequently Asked Questions

How Long Does It Take to Change an Alternator?

A seasoned mechanic can repair or change your alternator in around two hours based on the make and model. However, most repair shops may charge for the whole day’s labor.
If you are planning to replace the alternator yourself at home, without having any prior experience, it could take between 3 and 4 hours. If you don’t have any mechanical expertise, we recommend avoiding replacing your alternator on your own. You could damage your vehicle or cause injury to yourself when working with electricity.

How Long Does an Alternator Last?

The alternators have a longer lifespan than car batteries. On average, the alternator lasts between 4 to 7 years. However, it depends on how frequently you drive your vehicle. Most vehicles require an alternator replacement at 40K to 80K miles. It won’t be in trouble for a brand-new car until it hits the 80K mile range.

How Much Does It Cost to Replace an Alternator?

The cost depends upon your car’s model and make. The service cost may range anything between $100 to $400. The labor cost would be around $120 to $200. The cost of the parts bought from the dealer will be higher. So the overall cost to replace an alternator, based on the model and make of vehicle, could cost you between $350 and $1000.

How Long Does It Take a Mechanic to Change an Alternator

Replacing an alternator is a two-hour job for a professional, but that doesn’t mean your car will only be at the shop for two hours. You may have to wait for a mechanic to become available, and if the shop needs to get parts delivered, it could take even longer.

Closing Words

You would need about two hours to change an alternator after you have replaced it earlier. Always make sure to use high-quality original parts in the process of replacing an alternator. It is essential to be cautious when handling electricity and check your vehicle’s manufacturer manual prior to beginning the process.