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Will Bad Alternator Cause Car to Stall? (Answered)

Alternator being an integral part of a car helps it to run smoothly by charging the car battery every time so that it can power up the engine and other electrical systems. 

Thereby, the thought of having a bad alternator in your car naturally will make you concerned enough that you may ask yourself will a bad alternator cause your car to stall or not.

Therefore, go through the detailed explanations ahead to end your concern and get answers to your queries. 

Will Bad Alternator Cause Car To Stall?

A faulty alternator surely will cause a car to stall. It’s because when an alternator goes bad, it becomes incapable to keep the car battery constantly charged, thereby, fuel injectors will not fire and it will cause the car engine to stall while the car is being driven. 

An alternator is one kind of electrical generator that is installed in cars to convert the chemical energy into electrical energy so that it can consistently keep charging the car battery to keep powering up the car’s engine to run the car smoothly.

So when the alternator starts to fail or has become totally faulty, it loses its capability of converting chemical energy into electrical energy. As a result, it won’t be able to charge the car battery consistently. 

And if the car battery isn’t fully charged, the fuel injectors also will not ignite the fuel, therefore, the engine will stall while driving the car which basically means the car will stall.

And if the car has a petrol engine or SI engine, a faulty alternator will stop powering up the spark plugs which are responsible for igniting the gasoline in the car’s engine. Thus, the engine ultimately will stall making the car stall too.

What Are The Symptoms Of A Bad Alternator?

An alternator shows several symptoms before going completely bad. Below the main symptoms are listed and have gone into detail so that you can recognize a faulty alternator.

The Warning Light

When an alternator starts to malfunction, a battery-shaped warning light often marked as “ALT” OR “GEN” will pop up on the car’s dashboard and it’s one of the primary symptoms that indicates that an alternator is perishing.

It’s because the warning light is there for indicating an alternator issue when the voltage at what an alternator works (between 13-14.5 volts) either declines below or exceeds the voltage limit.

Dim Or Bright Or Flickering Headlights:

Too bright or dim or flickering headlights are another very strong symptom that indicates a faulty alternator.

When the alternator starts to malfunction, it struggles to supply constant electric power to the headlights. As a result, the headlights will start dimming or will light up too brightly. Sometimes, headlights can flicker as well and they erratically will go from too bright to dim or vice versa.

Malfunctioned Electrical Systems:

An alternator is also in charge of supplying electricity to a car’s various electrical components such as power windows, air conditioning, door locks, car radio, heated sits, etc. So when the alternator will start failing, these electrical systems will start malfunctioning too.

Therefore, upon noticing any malfunctioned electrical system, know that it’s a faulty alternator issue.

Strange Sounds:

The car makes very strange growling or whining sounds when the alternator goes bad and it’s of the main symptoms of a failing alternator. It happens when a faulty alternator makes some bearings failure in the car’s engine that creates strange rattles.

Strange Smell:

A strange smell of burning wires/rubber is a major indicator that says that an alternator has started to wear out, as the drive belt of an alternator at that time is going through consistent tension and traction. 

Thereby, it creates heat as well as a burning rubber-like smell while making the alternator go bad.

Similarly, when the alternator has overworked or has damaged wires, a burning smell will start to emit which also indicates that the alternator has gone bad.

Why Do Alternators Go Bad?

After knowing the symptoms of a bad alternator, you might wonder what are the causes that make an alternator go bad. Therefore, go through the list below to learn those reasons.

An Aged Alternator:

An alternator goes all bad due to getting aged or exceeding its average lifespan and it’s the most obvious reason.

Generally, an alternator comes with 5-8 years of lifespan, so when this maximum lifespan of an alternator will come to end, it naturally will go bad as it has been used fully and has aged enough, therefore, its parts are worn out.

Wiring Problems:

A car has lots of wires that supply power to an alternator to function properly. When one of those wires gets damaged, it makes the whole alternator struggle to perform its job properly. And gradually the alternator goes totally bad while struggling to function accurately.

Broken Belt/Broken Pulley:

The alternator belt and pulleys aren’t very durable as a result, they can get damaged or broken easily. Besides, over time these pulleys can get down out due to their age and usage, belts can also start cracking after a certain time.

So if either of them happens, an alternator failure will occur.

Computer Problem:

Cars are now built with computer systems like the ECU, and these computer systems virtually control every part of the car which includes the alternator too. 

So if there a problem occurs in the computer system, it will make the alternator stop working and charge accurately even if it is a well-functioned alternator.

Bad Fuse:

Vehicles have fused to keep the alternator functional. If one or more blows out or if power surges, the alternator will go bad.


Engine oil or the power steering fluid sometimes can get leaked and go enter into the alternator which can cause an alternator failure.

What Problem Can A Bad Alternator Cause?

The major symptoms of a bad alternator are the major problems that a faulty alternator cause to a car. So here, except for those symptoms/problems, the rest are listed and explained precisely below.

Difficulty Starting:

A bad alternator obviously can’t recharge the car battery sufficiently every time, thus, the battery will not have enough electrical power to power up the car engine to run the car smoothly. 

As a result, the car will initially create difficulty in starting it while wanting to drive the car.

Drains Out The Car Battery:

A bad alternator indeed can cause a car battery to drain out. When the alternator starts to fail, the battery starts to take upon the slack on itself instead of working like a capacitor for the car’s system by getting consistent electrical power from that alternator. 

Thereby, the car battery’s charge eventually will deplete sooner than usual times making the battery drain out fully and the car not start at all.

Can You Drive The Car With A Bad Alternator?

Technically, you can drive a car with a faulty alternator but it is not suggested at all, especially if your car is a newer model one because more electricity is involved in a new model car in comparison to an older car model. So, a bad alternator can cause serious problems for the car.

However, if you really want to drive with a bad alternator, you can make it up to veryfew miles only down the road.

How Long Can You Drive A Car With A Bad Alternator?

You can drive a car with a bad alternator for about 5-30 minutes maximum as most of the time the car battery only can last up to 30 minutes when the alternator is bad. 

However, if you are fortunate enough, you can even tin a car with a bad alternator for as long as 2 hours, but it’s a very rare scenario and only can happen if the battery has full charge.

How Much Does It Cost To Replace An Alternator?

The average cost of replacing an alternator ranges between $100-$350, however it depends on the model and make. If any extra part isn’t required to be changed, the entire job of replacing an alternator will be done within an average cost of $350-$400.

In case you have included the serpentine belt too in the replacing process, add an extra $20-$50 in the total bill.

Is It Worth Replacing An Alternator?

It’s really worth replacing an alternator entirely if it’s not working properly because it will eventually do the job of running the car and its electrical systems quite accurately. But don’t expect it to work as efficiently as a new one.

If you don’t want to spend money on a new alternator, replacing it is worth enough.

Final Thoughts

Having a crucial part in running a car smoothly, a bad alternator will make the car stall. Because a faulty alternator fails to convert chemical energy into electrical energy, thus, it fails to recharge the car battery sufficiently. Thereby, the battery can’t power up the engine, and the car stalls.