The alternator is one of the undervalued parts of the car. We focus too much attention on the battery, ignoring the fact that the battery can neither store nor distribute electric energy on its own. It turns out that even this “mighty” power storage (car battery) must work simultaneously with the alternator to power the car.
Alternators have a useful life of up to seven years. By this time, you’ll have approximately covered between 100,000 and 150,000 of driving mileage. As you approach these timelines, your alternator tends to misbehave, often showing signs of failure.
While you can still start and drive your vehicle with a faulty alternator, this habit exposes your car to critical equipment damage. Not to mention the danger of personal injury or even road accidents associated with driving under unstable alternator conditions.
To fully understand the risks of driving with a bad alternator, we must first appreciate its usefulness in our cars.
What Does an Alternator Do in My Car?
Simply put, an alternator performs the critical function of regulating the battery charge to maintain a steady flow of power in the vehicle’s electrical system. It controls the battery’s power input as well as output.
On the one hand, an alternator is responsible for continuous battery recharging. This means that it converts the AC power generated by the running engine to DC power, which is required to allow storage in ordinary lead batteries.
On the other hand, an alternator controls the amount of electric energy consumed by various electric-powered components in your car. For instance, it supplies the headlights with high-voltage power when it is switched to full lights mode and moderate voltage when the low beam switch is engaged.
Alternators play an even greater role in powering the current generation of cars. Unlike the traditional models that were largely run on manual technologies, the emerging makes rely on electrical power to operate nearly every aspect of the car. With this level of sophistication, your car requires a steady supply of electrical power to guarantee a safe drive. That is why it is crucial to always have a functional alternator.
So, what are the dangers of operating a car with a faulty alternator?
Risks of Driving With a Faulty Alternator
A Bad Alternator Causes Delayed Engine Starts
The most common issue of driving with a bad alternator is that you’ll experience delayed starts. This is caused by the alternator’s inability to generate sufficient DC voltage to charge your car battery. You see, a partially charged battery doesn’t have adequate power to ignite your car engine.
Also, a faulty alternator can cause internal short-circuits, leading to drastic battery draining. This leaves your battery in a flat mode, completely losing its capability to start the engine. In such cases, you’ll be forced to draw power from external batteries to ignite your engine.
A Failing Alternator Drains Car Battery
A bad alternator often fails to maintain a battery’s charge. This fault allows steady and rapid depletion of the stored battery charge. As a result, you suffer the inconveniences of a partial or fully dysfunctional battery, such as unresponsive car accessories and delayed engine starts.
Automotive experts argue that this risk does not pose serious functionality issues to your car since you can always resort to an external power source. Even so, this outcome exposes you to all manner of dangers, including causing irreversible sulfation on your battery.
When sulfation occurs, it is time to budget for a new car battery as it often leads to irreversible damage.
A Faulty Alternator Can Cause Irreversible Battery Damage
Driving with a faulty alternator often leads to battery overcharge. This causes irreversible damage as the battery’s internal system is exposed to uncontrolled electrical input.
So, the longer you drive with a dysfunctional alternator, the more your car battery is overcharged. Eventually, you come to a point where crucial components of the battery are completely damaged. This outcome forces you to incur the cost of battery replacement.
Such alternator issues are the main reasons why motorists undergo multiple battery replacements. Often, car owners, as well as their mechanics, realize this problem when it is too late—after they have tried more than one battery.
It’s a good thing that the current crop of mechanics is increasingly realizing that car battery damages are mostly due to alternator faults. So, they tend to apply diagnostic best practices, requiring them to check the state of alternators along with every battery change. This practice helps differentiate the identical failure signs in a car battery and an alternator.
A Bad Alternator Can Undermine Your Driving Control
A broken alternator can lead to a loss of control while driving. This problem is common in the current generation of cars that are hydraulically or electrically powered as opposed to manual.
These models rely on an uninterrupted source of electrical energy to power the critical functions, including the steering and braking systems. So, if battery and alternator instability lead to inadequate powering in these essential areas, the vehicle’s overall stability on the road is greatly compromised.
A Bad Alternator Can Damage the Car Engine
A faulty alternator poses all manner of risks to your car engine, and the danger is even greater for newer vehicle models that use electric energy. Some of the electric-powered components include the water pump, steering pump, fuel pump, and brake booster.
So, how does a faulty alternator affect the engine’s long-term functioning? For instance, if an electric water pump stops due to an alternator-related hitch, the continued running of the car will overheat the engine. Overheating alone causes severe, and sometimes permanent, damage to the engine’s crucial components.
This is an illustration of how a single electric-powered component (water pump) can cause irreversible damage to your engine. So, imagine a situation where a vehicle’s multiple components simultaneously malfunction as a result of an alternator-related glitch.
So, how do you detect a bad alternator? Let’s analyze the common signs!
How to Detect a Bad Alternator
Here are the major signs that can help you detect a failing car alternator.
Battery Warning Light on the Dashboard
It’s easy to assume that the battery warning light is limited to the battery-specific problem. Well, that’s not always the case, so don’t jump to that conclusion.
A battery warning light in your dashboard points to the presence of an issue in the larger electrical system, which can be an alternator, a battery, and wired connections.
And since an alternator requires a specific voltage input (between 13 to 14.5 volts) for proper functioning, a drop in voltage capacity can be a sign of its failure.
So, if your alternator is broken, a slight voltage drop is automatically reflected in the dashboard as the two components (battery and alternator) are conjoined to function simultaneously. Use these hints to rule out some of the obvious electrical problems.
The warning light also comes on when the alternator exceeds its voltage limit. In this case, failure is predicted since a properly functioning alternator would limit the amount of power output to match the battery’s intake capability.
So, if the battery warning light goes on, ask your mechanic to check all three electrical components (an alternator, a battery, and wire connections) to confirm the exact source of the hitch.
Dim or Very Bright Light
Dim or overly bright light is an obvious sign of a failing alternator. This situation is caused by inconsistent power output from the alternator, supplying either too little or too much voltage to your electronic components.
So as not to misinterpret this issue as battery-related—as is commonly the case—you should read the trend of under or over-performing accessories. Too dim or too bright lighting in accessories, such as headlights, rules out the battery-specific problem. A mere battery problem would naturally lead to a steady dimming behavior as opposed to inconsistent lighting that goes from dim to bright and vice-versa.
Slow or Unresponsive Accessories
If your car’s alternator isn’t supplying enough voltage to power the electronic components, there’s a high chance that it is faulty. To take you back a little, the alternator’s primary role is to ensure a steady supply of power throughout the vehicle’s electronic accessories, such as windows, seat warmers, radio, and speedometer, among others.
Thus, a slow or zero response in any of these dependent components can only indicate a fault in the alternator.
Uncommon Noises and Smell of Burning Rubber
Growling or whining sounds from under the hood can indicate serious alternator problems. These noises originate from the misaligned belt, which rubs against the walls while turning the alternator’s pulley.
Therefore, since an alternator is designed to operate with a perfectly fitting belt, even the slightest form of misalignment can lead to the most irritable noises under your vehicle’s hood. Obviously, any form of belt misplacement points to severe mechanical malfunctions in the alternator.
Another sign of a mechanical issue in the alternator is the smell of burning rubber. This smell originates from the worn-out drive belt, which can barely withstand the alternator’s heated tension and friction. So, when you notice such weird noises or smells, it is time to visit your mechanic for an alternator check.
Also, find out how long you can go without an oil change.
The risks of driving with a bad alternator narrow down to the typical mechanical complications. These complications, in turn, can translate to serious issues, including irreversible engine failure and costly driving inconveniences. At the very least, driving with a broken alternator reduces the lifespan of your car battery and can lead to minor challenges, such as delayed engine start and unresponsive electronic accessories.