When you turn the key for the ignition but nothing happens except that you hear the click sound. It can be confusing whether the battery is dead or there is something more serious. Generally, everyone would assume that battery is faulty but when you change the battery, it gets drained again and becomes dead. So where is the problem? Here, the
Alternators can be the real culprit that has become faulty and stopped charging the battery and supplying power to other electric systems.
To understand how it affects the overall performance of the vehicle, you should know how it works and what the early signs of failing Alternator are.
Let’s scroll down and know everything in detail.
What Does an Alternator Do
We usually think the battery alone runs the electrics in our vehicle, but it’s not true. The battery only provides electricity for that initial spark called ignition so that the engine car start. Once the engine starts running, the alternator takes over and generates electric power while the engine is running. It charges the battery and supplies power to different electric parts of the vehicle including engine, car lights, stereo, dash lights, and power windows.
The Alternator is the key component of the vehicle’s charging system that is turned by the engine’s serpentine belt. However, it has a good lifespan of 8 to 12 years but it may go bad before that also. Having a bad alternator brings a number of issues such as dim light, dead car battery, and even engine stalling. Therefore, it is essential to take your vehicle to an expert mechanic when you notice such issues.
How Does a Car Alternator Work
Automotive batteries are not enough to meet the need of the power of different electrical systems present inside the vehicle. This is where Alternator comes. It supplies power to different electrical accessories as well as charges the battery.
Let’s see how a car Alternator works-
The Alternator turns mechanical energy into electrical energy and for this, it relies on electromagnetic induction. Electromagnetic induction occurs in two ways either when a conductor passes through a magnetic field or when a magnetic field passes through a conductor. The Alternator relies on the second method in which the conductor remains stationary and the magnetic field rotates.
1. The Stator And The Rotor
The Alternator has two major components Stator and Rotor which work together to turn mechanical energy into electricity. Here the Rotor is the magnetic field and the Stator is the conductor. They are placed such that the Rotor is the magnetic iron core positioned inside the Stator that includes copper wire called copper windings.
The Rotor is further attached to the spinning belt. When your vehicle is running, the spinning belt turns the Rotor and when magnetic Rotor spins inside the copper windings the alternating current is generated. But the vehicle can’t use this alternating current and now there is the need of Diodes.
This is another important component of an Alternator. It allows current to pass in one direction and also converts alternating current (AC) into direct current (DC) that the vehicle can use.
3. Voltage Regulator
To control the charging process, how much power is distributed from the Alternator to the battery also needs to be controlled. And Voltage Regulator is the component that controls the output of electricity being transferred to the battery. The voltage regulator can be externally placed or can also be inbuilt. However, in modern vehicles, the function of the Voltage Regulator is performed by the Engine Control Unit itself.
Also, Read: Symptoms of Bad Engine Control Unit (ECU)
Signs and Symptoms of Bad Alternator
#1 – The Indicator Light
This is usually the first Symptoms of Alternator Going Bad that the drivers notice. The indicator light either shows the “ALT” for Alternator or “GEN” for the generator. This alerts you that something is wrong with the alternator or the battery. If you notice this sign, take your vehicle to an expert mechanic for a thorough inspection.
Related: How to Reset Check Engine Light
#2 – Flickering Headlights
The Alternator provides power to the headlights and if you notice the headlights are dim or flickering, it gives the clear indication that Alternator is about to die. You may also notice that some of the electronic accessories that are powered by the Alternator such as power windows and power seats have become quite slow while operating them.
The dim light on the dashboard also indicates that you need to get the Alternator checked.
#3 – Weak or Dead Battery
A weak or dead battery is another sign that Alternator is failing. The Alternator supplies power to the battery and if the battery is weak, it means it’s not getting power from the Alternator.
However, the battery can be dead on its own over time. To ensure whether the culprit is the Alternator or the battery, perform an easy test. Charge the battery and start the vehicle, if the battery is weak or dead, the vehicle still continues to run but if the Alternator is malfunctioning, the vehicle will not start.
#4 – Strange Noises
This happens when any of the internal parts of the Alternator gets worn or breaks specifically, the worn-out bearings inside the Alternator cause unusual rattles.
These unusual noises coming from your engine indicate to Alternator failure. But there are so many reasons for unusual noises. Therefore, if you notice odd sound along with some of the symptoms given here, these all can indicate a failing Alternator.
Related: Car Makes Humming Noise
#5 – Difficulty Starting Your Car
The alternator provides power to the spark plugs that ignite the gas in the engine and keeps the vehicle running. If the alternator is about to fail, there might not be enough power in the spark plugs to start the vehicle or keep it running. And you will experience sudden stalling, if this happens, it could indicate a problem with your alternator.
#6 – Electric Failures
When the alternator is going to fail, all of the electric systems that are powered by the alternator will either stop functioning or act slowly. The main systems that would get affected are power locks, air conditioning, power windows, radio, and dashboard lights.
However, there could be other possible reasons for this electric failure, therefore, it necessary to take the vehicle to an expert mechanic to have the problem diagnosed.
What Happens to Your Car When Alternator Goes Out
1. What Problems Does a Bad Alternator Cause
When you have a bad Alternator, your vehicle hardly starts when you turn the key in the ignition and switch on the start button. If there is any power left in the battery, the ignition may happen but only for some time till the engine eats up the battery power. All the electric systems would stop functioning.
Being the key supplier of power to the battery and other electric systems of the car, the bad Alternator leaves the car useless.
The most dangerous thing that can happen with a faulty Alternator is when the bearing of the Alternator gets failed or damaged. If this happens, it stops turning and put the whole stress on the belt that causes it to snap. And if the belt snaps, it can cause heavy damage to the other internal parts of the engine. While if the rotor fails, it would hardly affect the electrical system but major damage would not happen. And if you get the things right early, there is a possibility that no damage will cause.
2. Would a Bad Alternator Cause a Car not to Start
Yes, of course, the car would not start if it has a bad Alternator. As the bad Alternator would not be able to charge the battery and also would not supply power to the engine and other electric systems of the car. And thus the car engine would not get power to cause ignition which would result in engine stalling.
How Much Does it Cost to Replace an Alternator
Your car’s Alternator is the most important part of the charging system. If it goes bad, it would stop supplying power to the car battery and once the battery power gets depleted, you would not be able to start the car. If this is the situation, the best solution is to replace the Alternator.
How much it will cost to replace an Alternator depends on the type and model of your car and where you buy the replacement alternator from. Generally, it costs from $170 to $400 for the replacement part and you can expect to pay between $200 and $450 as in labor cost for the replacement of Alternator. Thus, the total Alternator replacement cost would fall between $400 and $900.
The labor cost majorly depends on the location of the Alternator. If it is located somewhere under the engine, it will be more difficult and time consuming to replace the Alternator. And this will increase the labor cost to replace the Alternator.
But if it is located on the outer part of the engine bay, it will be easier to access and take less time to replace it.
Frequently Asked Questions
#1. Can You Drive with Bad Alternator
A car can run with a bad Alternator but only for a short time. Once the battery’s charge is depleted and the alternator isn’t recharging it, your engine will not get power and eventually cause stalling and your car won’t restart.
#2. How to Test if Your Alternator is Bad
If you have recently connected a new battery and now your car is not getting started. The problem may be with the alternator that is not charging the battery. But how can you tell that this is the Alternator and not the battery.
You can be assured of which one is faulty – the battery or the Alternator. You only need to perform a simple test.
Tool Required: Multi-Meter
- Step #1: Open the car hood and locate the Alternator. Check if the Alternator belt is loose. If it is not loose, move to the next step.
- Step #2: Turn on the engine; check out the Alternator belt is spinning properly.
- Step #3: The voltage testing of the Alternator can be done in two ways. First, you can touch the positive probe of the multi-meter to the positive terminal connector of the Alternator. And touch the negative probe of the multi-meter to some metal part of the car frame (you can also touch it to the negative terminal of the car battery). And see the reading being shown on the meter.
If the Alternator is located somewhere under the engine and it is much difficult to get access to it. Then you can simply connect the positive probe of the multi-meter to the positive terminal of the battery and similarly the negative probe to the negative terminal.
If the reading on the meter display comes between 13.8 volts and 15.3 volts, it means Alternator is working perfectly. If the reading comes below this range that means Alternator is malfunctioning. And if it is above 15.3 volts, the Voltage Regulator can be defective. But for accurate diagnostic, you may require special equipment. Therefore, if you find higher reading, take your vehicle to the professional mechanic.
Having the car Alternator replaced can be quite expensive and hectic too. But after knowing how critical it is for the safety of your vehicle, it is worth the replacement cost. Here, the reconditioned Alternator can be a good alternative to a new one. And you can get this at a substantially low price. So, don’t worry if you have a bad Alternator.