My Car Keeps Burning Out Alternators: Why Is It Happening? 11 Things To Check

Are you fed up with having to go to the auto repair shop every few days with a dead battery? Wondering, “why does my car keeps burning out alternators?” keep reading to learn everything there is to know about bad alternators in your car.

When you are driving back home after a long day, the worst thing that can happen is if your car suddenly makes a strange sound and comes to a halt. Sound familiar? That is because a bad battery or, more likely, a burnt-out alternator is one of the most common problems to occur in your car. 

In today’s article, we will be discussing car alternators and why you run into so many problems with them so often. And is there anything you can do about it? 

Read on to find out.

My Car Keeps Burning Out Alternators

Also read: What to do if your car does not start and the gauges keep fluttering

The Basics Of A Car Alternator

For those who are new to the world of cars, an alternator is an essential component that helps to recharge the car battery. The main purpose is to keep the battery functional even when it is getting discharged. 

The alternator supplies the engine with the correct voltage needed to start and keep moving. It also considers the voltage being consumed by the battery so that the battery does get discharged randomly. How the alternator of your car functions also depends on how many accessories you have connected to your car and how much power it is taking up from the battery. 

So when you are facing problems with the alternator, your battery is drained out completely and brings your car to a stop. You will not be able to start the vehicle, indicating that the alternator has likely burnt out. Unfortunately, this is a common problem in a lot of cars and occurs frequently. 

How To Identify A Burnt Out Alternator?

Just like any other machine, your car will exhibit clear signs when it has a burnt-out alternator.

Let us tell you about the main signs that you need to look out for.

1. Dead Battery

A dead battery in a car occurs over time and is a signal that your battery has finally reached its expiry date. But it can also happen if you have left your car lights on for too long. However, in some cases, a dead battery can be an indication of a burnt-out alternator. 

Alternators are used to recharge the battery and keep it from getting fully discharged frequently. If this component is malfunctioning, you will find that the charge in your battery is decreasing faster, even with limited use. A burnt-out alternator means that there is not enough power in the alternator to keep your battery recharged throughout the usage of the car. 

One idea to test the actual cause of a dead battery is to jumpstart your car. If you jumpstart the car and it keeps running, it is a sign that the battery needs to be replaced soon. But if the car starts and then stops after the jumpstart, the problem is with your alternator. 

2. Accessories not running smoothly

A malfunctioning alternator can have a similar effect on different accessories in the vehicle. The windows may roll up or down slower than normal, seat-warmers might be less effective, and sometimes the speedometer can stop working. 

Failing lights of a car are one of the first signs of a burnt-out alternator. An alternator is responsible for managing the voltage of the vehicle, so the lights will be affected when it starts malfunctioning. Usually, this would happen by the lights getting dim or very dark, or in some cases, the lights start to flicker. 

In a lot of car models, the first thing to get affected by a faulty alternator is the computer system of the car. You lose power on the radio and Bluetooth system and then see the lights flickering. The non-essential components in a modern car are the first things that get affected. 

3. Whining or Growling Sounds

It is no secret that cars make a lot of noise – some are annoying but harmless. But there are some noises in the car that are just alarms for trouble. If you have been hearing a growling noise from any part of the car, it is probably a mechanical issue that needs attention. 

A growling or whining sound in the car can be traced back to an alternator issue. The sound can usually be heard from under the hood when there is trouble with the belt of the alternator’s pulley. If the belt is aligned in the wrong way or has slipped from its main path, friction is created between the parts, causing loud sounds.

My Car Keeps Burning Out Alternators

4. Smell of Wires of Rubber Being Burnt

The odor of burning tires is a very distinct smell that most people will recognize easily. If you suddenly smell burning rubber or tires, it could be a sign that your alternator is getting damaged in some places. The odor could be an indication of the parts wearing out, mostly like the alternator’s belt, which is located close to the car engine.

If there is a poor connection of the wires around the alternator, causing the component to overwork, there could be damage to the wires around. This loose connection can cause surrounding parts to overheat, and if there is a dangerous temperature rise, you will likely get a burnt tire smell. 

5. Battery Warning Showing Up On Your Dashboard For No Reason

The battery warning light on the dashboard is a sign that there is some internal trouble that needs to be checked. In most cases, there could be trouble with the battery, but sometimes, it is a sign of a failing alternator.

When the alternator in your car cannot manage the voltage requirements of the various accessories, the battery warning sign might start to show up on the dashboard. The average alternator has a voltage capacity of 13-14.5 volts. If the voltage capacity goes down, the battery sign can indicate that there is a problem.

6. Car Stalling or Not Starting At all

When you have trouble starting your engine, it is a clear sign of problems with your car’s alternator. Usually, it means that the alternator is failing to charge the battery, which will enable you to start the vehicle after it has been stationary for some time. 

You should also look for signs if your car keeps stalling while you are driving. This is a warning that the spark plugs in your alternator are failing. Normally the issue is that the spark plugs are not getting the power required to keep the engine running. 

What Could Cause A Brand New Alternator To Burn Out?

Sometimes, you can start using a new alternator and find out that it is burnt out. Frustrating as the problem is, it can occur for a number of reasons:

  • Using the jumper cables incorrectly: Jumper cables are used by a lot of drivers when the battery gets discharged. While this does the work of starting the car at the moment, it can damage the alternator, burning it out in most cases. 
  • Leakage: Fluid leakage is a very common issue that causes alternators to fail. If there is any kind of fluid leaking on the internal components, there is a higher chance of corrosion and wear. This can damage the alternator very quickly. 
  • Wrong voltage: The average car battery needs 12 volts to start up the engine. If the battery in your car is using 14-16 volts, depending on the model, it means your alternator will be overworking. This difference in voltage capacity can burn out the component. 
  • Using bad-quality alternators: If you are going for a cheap alternator from some non-reputable manufacturer, there is a chance that you are signing up for trouble. There are smaller brands that use poor-quality materials to make the component available for a lower price. But most of these will burn out after brief use. 

How Long Does An Alternator Last?

The lifespan of an alternator depends on how you are using your car and what kind of accessories load you have. An average alternator lasts between 90,000 and 120,000 miles, likely eight to ten years. Some manufacturers suggest that an alternator can be used even after its expiration time if there are fewer number of accessories.

The capacity of an alternator depends on how much load you are putting on it. If you have multiple accessories that use up the battery, it is possible that the alternator will last less than expected. Disconnecting some of these devices can help you increase the lifespan of the alternator. 

My Car Keeps Burning Out Alternators

Why Do Car Alternators Burn Out And How To Manage The Problem?

If you are trying to figure out what are the causes for your alternator to fail, there could be a number of reasons you have to look into. But knowing the exact cause can help you to sort out the problem quickly before more damage is done. Here are some of the most common causes for your alternator burning out. 

1. Improper installation of the alternator

One of the most common reasons for an alternator to malfunction is if it is not installed properly. If there is some issue with the placement of the component or it is not able to work in connection with the battery, it will obviously fail to perform its function.

2. Car modifications that draw a lot of power

There are certain components in a car that are referred to as non-essential components, like the stereo and radio system, etc. These draw power from the engine but are managed between the alternator for distribution. 

When you start installing more accessories, the alternator has to modify its function accordingly. So if there are too many extra points of power, the alternator will be overloaded very easily and wear out quickly. 

3. High resistance in the charging output circuit between the alternator and battery

If there is high resistance in the output, it can directly have an effect on the alternator, often causing it to burn out. In most cases, if there is a wiring issue with the output circuit, it will cause a high power difference between the battery and the alternator. It is one of the most common issues that cause an alternator to be damaged. 

4. Heat from the exhaust gets onto the alternator

Heat damage to the alternator from any kind of exhaust system in the car could be a real problem for the alternator. The component has a belt and wiring that can be affected by overheating. Alternators are also located very close to the engine, which makes it more susceptible to heat damage. 

5. Poor quality alternator

Like any other mechanical component, if you have an alternator that is of poor quality, you can expect to run into trouble very soon. If you find that your car’s alternator is burning out very soon or overheating with the slightest use, it is likely that you have got a bad alternator in your car

A number of automobile manufacturers use alternators of bad quality to reduce production costs. So, when you are replacing the damaged one, make sure you contact a reputed manufacturer. 

My Car Keeps Burning Out Alternators

6. Corrosion near the terminals at the battery and the alternator

If there are damaged terminal connections at the junction of the alternator and battery, you are likely to find out that the alternator will get damaged very quickly. The loose wires, corrosion in terminals, and poor connection between the components will not allow the alternator to function properly. 

If your battery is getting discharged quickly or you see that there is some kind of loose connection in your car, it is probably because of the terminals being corroded. 

7. Bad battery

If your car has a damaged battery, more specifically, if there is a leakage in your car battery, it has a high chance of damaging your car’s alternator. In case of a damaged battery, there is more current drawn from the alternator, causing the component to overheat and start burning out over time. 

8. Faulty Starter or Solenoid Coil

In a car, the starter is the device that is used to fire up the engine once you have turned on the ignition. It uses sparks that can create enough voltage to result in the car moving forward. And the starter is engaged by using a solenoid coil.

If there is a problem in either of the set-up, the solenoid will not be sending enough voltage to the starter. Over time, the starter will be damaged and not be able to receive any voltage. This will affect the alternator in receiving current and getting the engine to work. 

The voltage of the starter can be checked with a voltmeter to see if it is functioning properly. The normal range should be 12 volts when the ignition is turned on. Below 12 volts indicate that there is a fault in the solenoid coil or the starter itself.

9. Bad Engine Control Module (ECM)

The Engine Control Module, abbreviated as ECM, is a system with sensors that measure the parameters of an engine. Accordingly, the ECM controls the operations of the engine by using actuators. When this system is faulty, the voltage sent to the alternator will not be correct and cause the accelerator to fail since the voltage levels will not be managed properly. 

My Car Keeps Burning Out Alternators

10. Excessive Carbon Build-Up in the Combustion Chamber

The space inside the engine where the fuel in the car is ignited to create energy is called the combustion chamber of the car. As a result of this, there is obviously a lot of carbon build-up in the chamber. 

When there is an excessive buildup in the combustion chamber, it will take more time to ignite the fuel and cause a drop in voltage. Once the voltage goes below a certain point, it is possible that the alternator will start failing. 

11. Leaky Intake Manifold Gasket

The component in the car used to direct the air into the engine is known as the intake manifold. The intake manifold gasket is the seal used to create a vacuum in the intake manifold from the rest of the car so that there is no leakage of any kind. 

If there has been a leakage in the gasket due to any reason, there will be a fall in voltage and eventually damage the alternator. You have to check the voltage at the intake manifold to make sure the leak is causing the alternator to burn out. 

How To Complete An Alternator Replacement By Yourself?

Replacing an alternator is not a very big deal, and you can do it by yourself with the right kind of tools. If you are not very confident about it, you can always pay a visit to a mechanic. But in case you want to try it out, here are the steps you need to follow:

  • Locate the alternator, which will usually be placed behind the engine in front of the car. If you have a problem locating the component, use a voltmeter. 
  • Remove the mounting bolts and disconnect the wiring that holds the alternator in place. 
  • Remove the alternator carefully and install the new one and reconnect the wiring correctly. This is an important step to follow because if the wiring is not done properly, the alternator is likely to fail. 

After everything has been secured, it is a good idea to get the system tested by a professional. 

My Car Keeps Burning Out Alternators

Frequently Asked Questions

What is the most common cause of a burnt-out alternator?

A failure in bearings or improper installation can be the most common cause of a burnt-out alternator. In either of these cases, the alternator is worn out due to friction or overheating, and you will not be able to notice the signs before it is completely damaged. 

What are the common faults in a car alternator?

Electrical problems, worn-out brushes, and damaged windings are some of the common faults in alternators. Most of these can lead to the alternator burning out very easily. You might run into trouble with the alternator if you are going for a cheap one from a non-reputable manufacturer. 

What happens when a car alternator goes out while driving?

If the alternator of your car goes out while driving, you will notice that your car is slowly losing power. This can happen when the car is slowing down or the lights get dim. If your alternator has completely burned out, you might not be able to start your engine once it stops. 

Can alternators fail suddenly?

No. Most alternators have a lot of warning signs before it finally fails, which mainly come in the form of electrical issues. You have to look out for signs like a heated seat, whirring noises, or flickering lights.  

What can damage the alternator?

A lot of things – corroded wiring, heat from the exhaust, a bad battery, leaky intake manifold, and so on. Excess load on the alternator is another reason why alternators burn out, and it is something that should make you consider whether you really need those seat warmers and bass speakers in your car.

My Car Keeps Burning Out Alternators

How long does an alternator last?

It depends on the make, model, and quality of the alternator. However, the rough idea is that a good alternator should last you about 90,000 to 150,000 miles, as long as you take good care of it and do not put excess load on it. Make sure that the alternator is checked regularly and that any bad wiring is promptly replaced.

Wrap Up

It can be a nightmare for any driver when the alternator gives out at the worst possible moment. This is why it is important to know the warning signs, know the steps of replacement, and above all, invest in a good alternator that can help you avoid the problem altogether. 

We hope this article helps you out the next time your alternator is causing any trouble mid-journey. Thank you for reading!

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Sean Mendez

Hi, I am Sean, a self-confessed petrolhead. I live in Boise, Idaho with a busy family of four and our energetic Labrador retriever. Thank you for visiting my website. You can find my email on the contact page.

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