If you own a car, you already know that your car’s electrical system plays a vital role in keeping your vehicle functional. At the core of the electrical system is the alternator, one of the most critical components in keeping your vehicle’s electrical system performing correctly. 

Yet as a driver, you might not know much about the alternator. What does it do? What signals should you watch for and correct before it fails altogether? 

What is an alternator?

Simply put, an alternator is a device that converts mechanical energy into electrical energy. The engine powers it and ensures that the battery remains charged. It also maintains a stable voltage supply to other electrical components in your vehicle.

The alternator is usually located near the engine. It creates electrical energy from mechanical energy with an alternating current. It’s created from several components, including:

• A voltage regulator to prevent power surges
• A stator and rotor to produce alternating current to convert energy into electricity 
• A cooling fan to protect the various parts from overheating

How does an alternator work?

The alternator takes the mechanical energy the engine generates through motion and turns it into electrical energy. This process is achieved using a rotor and a stator within the alternator. The rotor is a magnetic field created by a copper coil that spins along with the engine belt. The stator sits beside the rotor, takes the rotating magnetic field and uses it to produce an electrical current. Once the electrical current is generated, it flows through the car’s electrical system, powering the lights, radio, and other electrical components.

How long does an alternator last?

Like other components on a vehicle, the alternator will only last for so long. The lifespan of an alternator may vary depending on the make and model of your vehicle and how often you use it. 

On average, alternators tend to last between five to seven years. However, if your alternator isn’t working right, it may be worth inspecting it to see if it needs replacement. If your alternator stops functioning, it could drain your car’s battery or lead to a much larger electrical failure that could wind up being a costly fix.

What symptoms surface when an alternator fails?

Several signs indicate an alternator is failing or has failed. The most common warning sign is your car battery warning light illuminating your dashboard. This light signals that an issue has arisen within the electrical system that needs attention. Other symptoms may include your car struggling to start or irregular noises or smells. If you notice these symptoms, you should get your vehicle to a mechanic as soon as possible.

Weak battery

As the alternator’s ability to charge the battery decreases, it will eventually lose its charge and weaken. This may cause the engine to struggle or even fail to start altogether.

Battery dashboard light on

A common indicator of a failing alternator is the battery dashboard light. If this light illuminates, the alternator is not charging the battery properly, and the battery is being drained.

Grinding noise

A failing alternator can also produce a grinding noise. This noise can be caused by worn bearings or failing internal parts. If the stator and rotor don’t spin correctly, they may produce an unpleasant sound. 

Dim or slow-working electrical components

If the alternator is not providing enough power to the electrical system, the car’s components, such as headlights, radio, and air conditioning, may operate at lower capacity or slow down. This can also include other systems like power windows or door locks

Flickering or pulsating headlights

A failing alternator may cause the headlights to flicker or pulse, as the alternator is not providing a consistent flow of electricity to the car’s electrical system.

Burning rubber smell

A worn-out alternator belt or a failing alternator pulley can cause a burning rubber smell. This indicates the belt or pulley is overheating due to excessive friction.

Stalling or hesitation

A weak or failing alternator can cause the engine to stall or hesitate, as the spark plugs may not receive enough power to ignite the fuel and air mixture in the combustion chamber.

Any of these symptoms should be taken seriously and should prompt you to have your vehicle inspected by a qualified mechanic. An alternator that is not functioning properly can lead to a drained battery, which can leave you stranded, and cause other issues down the road if not addressed.

How do you fix an alternator? 

A qualified mechanic should always carry out the repair or replacement of an alternator. Ensure they have experience working on automotive electrical systems.  

Before replacing an alternator, the mechanic will perform a series of diagnostic tests to determine the cause of the issue. This may include testing the battery, checking the alternator’s voltage output, and inspecting the alternator belt and pulley.

Depending on the results of the diagnostic tests, the mechanic may be able to repair the alternator by replacing faulty components such as the voltage regulator or bearings. If the alternator cannot be repaired, it must be replaced with a new or rebuilt unit.

After the installation, the mechanic will perform a series of tests to ensure the alternator functions properly. This may include checking the voltage output, inspecting the battery’s charge level, and verifying that all electrical components work as they should.

Easy peasy, and it shouldn’t take much time. You’ll be back on the road in no time. 

Have you ever had a problem with an alternator? 

While an alternator may not be a component you work with regularly, it’s crucial to your vehicle’s construction. As it fails, your car will show visible signs of failure. 

The alternator is a critical element in how your car runs, and it is vital to know when it is showing signs of wear and tear or failing altogether. Knowing what an alternator is and how it works can be very helpful when talking to a mechanic about the issues you may be experiencing. 

Keep an eye out for warning signs, and if you ever feel unsure about anything, it’s always best to take your vehicle to a mechanic to get a proper diagnosis. You can avoid costly fees and expenses by staying on top of your car’s electrical system and ensuring the alternator is doing its job.

Many drivers on the road today have just a basic understanding of how their cars work.

The engine runs the car. The tires keep the car on the road. And gas and motor oil are needed regularly to ensure your car stays running smoothly.

But as you dive deeper, things get a little fuzzier. You may have heard words like “alternator” before. But hearing them and knowing what they do are two separate things.

When you turn the key (or press the button) and power turns on your radio, your headlights, and other electronic accessories throughout your car, what powers them? Most people guess: the battery. But that’s only half right. The battery may kickstart everything on. But it’s the alternator that keeps it all running.

What an alternator does

Every time you start up your car, it powers a drive belt that rests on a pulley, which is attached to the alternator. The battery provides the necessary power to start the car. Think of it in similar terms to a generator. The car’s combustion engine spins the pulley underneath the hood, which turns the pulley on the alternator, and creates energy. It converts mechanical energy into electricity.

Think of your alternator as your car battery’s charging system. It supplies the necessary electrical current for things like your ignition, radio, air conditioning, power windows, windshield wipers, and other electrical items throughout your car.

Inside is a voltage regulator that monitors the battery charge. As the battery runs low, the alternator supplies a power source to ensure it stays running. Without the two working together, your car wouldn’t run.

A car’s alternator isn’t something that will break down often. Alternators can last the lifetime of your vehicle. However, that doesn’t always happen. Every car on the road today wears down in different ways as it reacts to its environment. It depends on things like weather, heat damage, wear and tear, faulty parts, or frayed wires. If not caught early, it can impact a variety of other parts throughout your vehicle.

How do you know if your alternator is failing?

Dim or bright lights

When your car is running the way it should, the stream of light from your headlights will provide ample light as you drive. As an alternator fails, it supplies an inconsistent level of energy to the headlights, which will result in changes to the light source. Do your headlights seem brighter than usual? Can you barely see? They may also flicker or even act erratically as you drive, switching from dim to bright.

Malfunctioning accessories

While many people start to notice changes to the light source first, a failing alternator can materialize in different ways. The alternator powers all of the accessories on your vehicle. If you notice the windows taking longer to roll up or down, if your radio shorts on and off, or if your seats take longer to heat and cool down faster than before, it may be a sign of a problem with your alternator.

Because today’s modern cars are run by technology, your vehicle prioritizes which systems to shut down. It will limit power to non-essential systems like power windows or seat warmers, in order to keep more important systems operating. That’s why you should pay attention and have your car serviced as soon as you notice certain issues.

Dead battery

If you try and start your car and it won’t turn over, it may be a sign of a problem with your alternator. Of course, it can be just a dead battery. So a few tests can help you determine where the problem lies.

A bad alternator won’t properly charge the battery while the engine is running. One way to test this is to jumpstart your car. If you jumpstart it and the car stays running, it’s the battery. If, however, the car dies shortly after you jumpstart it, it might be the alternator. It’s not allowing enough power to properly power the batter while the car is operating.

Starting and stalling issues

If the alternator isn’t properly charging the battery, power isn’t flowing correctly through the system. Have you ever turned the key in the ignition and heard a clicking sound? That’s a sign of a problem with the power supply.

In some cases, you may be driving around, only to find your car stalls out periodically. This is a sign the engine isn’t getting enough power to stay running. The spark plugs aren’t receiving enough power, which brings the engine to a stop.

In either case, it’s important to get your car serviced quickly to ensure the safety of you and your vehicle.

Noises and smells

Like every system on your vehicle, there are certain noises and smells that are associated with different parts to help you indicate when there is a problem.

A problem with the alternator often causes a growling or whining noise from underneath the hood. The belt that turns the alternator can wear down, become misaligned, or rub other parts in the system, causing a noise. It also may whine as the bearing that turns the rotor shaft goes bad.

It can also materialize in the form of a foul smell, or even like burning rubber. Because the alternator belt is under constant pressure, and it’s located next to the hot engine, it can wear down and start smelling like burning rubber. If the wires are damaged and frayed, they can short and create a burning odor. If allowed to operate in this capacity for any length of time, it can potentially cause an electrical fire.

Battery light

Occasionally, your battery warning light might light up on your dashboard. This isn’t always a warning sign of a failing battery. Instead, it may be telling you something is wrong with the electrical  system, which could be the alternator.

Because the alternator is designed to work at a specific voltage, if it falls below that level, it can cause the battery warning light. If you’re using several accessories at once – headlights, windshield wipers, and heated seats, for example – the overload of power may impact the electrical load, causing the battery light to flicker.

Lighting up once may be a coincidence. If you start to notice it frequently, it’s time to let one of our mechanics check it out.