How Long Do Alternators Last? Plus Maintenance Tips
Due to their close connection with a car's battery, alternators' faults can be difficult to diagnose. The alternator, while equally crucial, is in charge of keeping the battery in good operating order. But how long do alternators last?
The lifespan of a new or rebuilt alternator is determined by the amount of work they need to do, as well as overheating and manufacturing methods. Today, we'll look at potential alternator problems and how long does an alternator lasts.
What is an Alternator? How Does It Work?
An alternator is a component of the engine that is responsible for supplying power to the battery. It keeps the battery charged and the vehicle's electrical and computer systems operational. Ideally, a car alternator is a generator that converts mechanical energy into electrical energy, which is then used to power various components in your car.
When it comes to how it works, the serpentine belt is turned by the engine's crankshaft, which spins a pulley on the alternator. As a result, the alternator produces alternating current (AC) voltage using electromagnetic induction.
This AC power voltage is converted to direct current (DC) voltage, which is then transferred through a voltage regulator and finally to the battery. The voltage regulator ensures the voltage does not exceed a level that may cause the battery to overheat and die.
How Long Do Alternators Last? (Average Lifespan)
When it comes to the question "how long does an alternator last?" there are several factors involved. A good number of factors work in favor of and others against alternators, making it a bit difficult to state how long an alternator will last.
However, an alternator is not designed to last the average life of modern vehicles. Generally, they are expected to last between 6 to 10 years or 80,000 to 150,000, on average.
Factors Affecting the Longevity of an Alternator
The alternating current is converted to DC power by six diodes passing through the rectifier assembly. Higher currents that are drawn from normal operation and electrical accessories will heat the diodes, causing them to heat up and, in certain cases, burn out or minimize their life span. Bad alternators will gradually lose their charge and die.
Furthermore, more current is needed to handle the electric fans running, heated seats and steering wheel, radio, and auxiliary amplifiers whenever the headlights are left on.
Under these circumstances, the alternator may fail prematurely. Normal functioning within the alternator's design restrictions assures that it will last for many years.
Signs of A Failing Alternator
Knowing if your alternator is failing can be difficult. A failing alternator has symptoms that are remarkably similar to those of a dying battery. This is because of the fact that they are both vital electrical power sources for your vehicle.
One electrical power source cannot exist without the other in a car's electrical system. They both rely on one another to keep the vehicle running smoothly. However, in most instances, your battery is more likely to fail than your alternator. Here are some signs that indicate a failing alternator;
1. Dimming Lights
When your headlights don't flash as brilliantly as they used to, you know there's a problem with the charging system or there's is a dying alternator. The interior lights may also flash from dim to brilliant in response to changes in your engine's RPM.
All of these are symptoms that your alternator is on its way out, and it's probably time for car owners to replace it. Drive your car to a facility where it can be repaired before it completely shuts down and can't be restarted.
2. Electrical Components Stop Working
Many essential features in modern vehicles rely on the car's electrical system, from headlights to dome lights, heated seats, heated steering wheel, GPS, and other features.
If some or all of these stop working or only work occasionally, there could be a problem with the charging system that will become worse and worse as the battery is drained. For instance, when you start your automobile, you may realize that the windshield wipers are not working properly.
Furthermore, if your car's electrical system is malfunctioning, you'll almost certainly notice an issue with the car's alternator. These electrical components will use a lot of the battery's power, and the battery will eventually lose its charge.
3. Warning Light
The check engine light should light up if the alternator fails or the battery is drained. If your vehicle has a separate charging system warning light, it should light up as well. Ensure that the serpentine belt is still in position by twisting the alternator pulley.
Don't turn off the engine as the battery may have lost its charge and lack enough power to restart it. You can also drive your vehicle to a garage and have the battery and alternator tested as well as the whole electrical system.
4. Burning Smell
When the alternator is striving to create enough DC under heavy electrical load, the rectifier's diodes will be heated. You might sense a burning smell coming from the alternator's region. The casing of the alternator may be hot enough to burn your hands, so avoid touching it.
How to Test An Alternator
Once the battery has been tested, the serpentine belt, alternator pulley, and serpentine belt tensioner should all be inspected.
If they are working properly, use a multimeter to examine and measure electrical output in the alternator by testing the battery voltage. It should read between 13.5 and 15 volts when the engine is operating. Ensure that it remains in this range even when the engine is running.
How to Replace Your Alternator
Individual alternator auto parts such as the rotor, diode pack, and stator are usually not serviceable. This means that if one of the car's components fails, the alternator should be replaced as a whole.

If you already have the tools and a basic understanding of automotive repair, you can save money on labor by replacing the alternator yourself. Always remember to consult your vehicle's service manual for the most up-to-date auto part details.
First, ensure that the car is parked in a leveled, well-lit area and that the engine has sufficient time to cool. To prevent yourself from being shocked, disconnect the battery.
The alternator is normally a silver, spherical device with a fan visible beneath the belt pulley in your engine bay. You may need two socket wrenches to break it loose because it's bolted to a bracket attached to the engine. It may be challenging to remove the bolts if the hardware is corroded.
Alternators can be driven by either a V-belt or a serpentine belt linked to the crankshaft. After the late 1980s, the previous began to fade, and serpentine belts are now standard on most new cars.
To remove the belt from the pulley, loosen the belt tensioner until there is some room in the belt. While you're at it, you might as well replace the belt whole.
Remove the electrical components and connections behind the alternator. The old alternator can then be removed and set aside. If you're going to replace the belt, do that first. After you've installed the new alternator in the proper location and tightened the belt, you may start tightening the nuts that hold the car alternator in place.
Lastly, replace the electrical components and connections, making sure they're in the right spot. Start the engine after reconnecting the battery.
Make sure your dashboard doesn't display any engine or battery warning lights and that you don't hear any unusual noises. If you do it correctly, your new alternator should last a long time and work just as it should.
Alternator Maintenance
Along with keeping an eye out for any warning signs, there are a few things you can do to help keep your alternator in good condition for as long as possible.
The following are a few general alternator maintenance recommendations:
Make sure you know how to jump-start the car properly; a bad jump-start can damage the alternator.
If aftermarket electronics are installed incorrectly, they might overload the alternator, so be cautious when adding high-tech accessories to your vehicle.
Keep an eye out for fluid leaks in the alternator, which can be detected by having the car serviced on a regular basis.
If you experience any of the warning signals of a failing battery, have the problem fixed. It's possible that the problem is with the alternator instead of the battery.
If you do need to replace the alternator, try to get a new one rather than one that has been "remanufactured."
You can extend the life of your alternator by following these guidelines, but keep in mind that even a well-maintained alternator might develop problems. It's critical to make routine auto maintenance a habit and have your vehicle inspected by a qualified local expert.
Frequently Asked Questions (FAQs) on Alternators
1. Can a car start with a bad alternator?
Yes, it might. However, that doesn't imply you should drive around with a faulty or dying alternator. Before you start driving, take care of the bad alternator first.
2. What causes the alternator to go bad?
Aging and wear, a loose or overtightened serpentine belt, parts contaminated with dirt, worn out brushes, failed bearings, eroding components, or improper connections can all cause the alternator to fail.
3. Do alternators fail suddenly?
If an alternator fails, it was most likely in bad shape before you detected any symptoms. So, an alternator can fail at any time.
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