Alternator replacement is part of the regular maintenance schedule. But if symptoms of a defective alternator are left unchecked, they can cause you a lot of trouble.
In this article, we’ll cover symptoms of an alternator replacement, its actual cost, labor, and systematic procedure to replace it by yourself.
Table of Contents
What is an Alternator?
In extremely simple terms alternator is a combination of a generator and rectifier. The generator part of the alternator produces current by using rotating magnetic coils and the rectifier converts the AC produced by the generator into DC.
The alternator is a major component of the electrical system of the car. It takes power directly from the output shaft of the engine. The rotating shaft is coupled with electric coils. These coils are placed between the north and south poles of the magnet.
The changing orientation of coils inside the magnetic field generates a current. But the direction of this current is alternating in each cycle. This alternating current is sent to a rectifier. The rectifier uses a combination of diodes to convert the alternating direction of the current into a direct unidirectional current.
What is the Function of an Alternator?
The alternators perform the following main functions:
- Powering of electronic components while driving
- Powering of components during idling
- Charging of battery while driving
We normally think that the car battery is responsible for providing power to electrical components. This is only partly right. A car battery is responsible for powering up electrical components only while the car is being turned on.
Once the car is up and running, it is the job of an alternator to provide power to your headlights, power windows, power seats, windshield wipers, radio, stereo, and all other electrical parts of your car.
Along with that alternator is responsible for charging your car battery while driving. The alternator sends direct current output to the battery that is responsible for charging it.
How Long Do Alternators Last?
The normal life expectancy of an alternator is 6 to 10 years. It needs to be changed after every 80,000 to 100,000 miles.
In most cases, the alternator can stay intact for your entire car life. But unexpected or early failures can occur due to wear and tear of coils, magnets, bushes, and other components of an alternator.
What Causes a Failed Alternator?
Most of the time it is just due to the fact that the life of the alternator has been reached, so it needs replacing. But sometimes it is due to your negligence. If you let the alternator run on an under-tensioned or over-tensioned serpentine belt, then it may result in a failed alternator. Eroded or rusted bearings and bushes can also lead to the extreme of a failed alternator.
How Much Does it Cost to Replace an Alternator?
The replacement of an alternator can cost somewhere between $350 and $750. It is fairly dependent upon the make, model, and year of your car.
How Much Does Alternator Replacement Labor Cost?
The labor cost for the replacement of an alternator can be between $100 and $250. This might vary if you visit an authorized car dealership or a normal car mechanic.
How Much Does the Alternator Cost?
The alternator itself is a costly part. Its price may vary between $100 and $500 normally. However, associated parts can cost you another $100 to $200.
The latest listings of alternators on Amazon start from $57 for Chevy Cavalier and go up to $5,774 for Bosch 536 model. Hence, these prices are highly variable.
What are the Signs of Bad Alternator?
The signs of a bad alternator are clear and confusing at the same time. Because the symptoms listed below can be caused by a faulty alternator as well as any other defect in the electrical system of the car. Still, if you observe any of the following symptoms you must not take it lightly and get your car inspected by a skilled electrician.
Overly Dim or Bright Lights: Flickering lights is the clearest symptom of an alternator nearing failure. As the alternator is responsible for powering up headlights so any minor voltage variation in its output can cause overly dim light or extremely powerful light causing glare.
Difficulty While Starting Car: Alternator charges up the battery of your car while it is running. If the alternator isn’t working correctly then the charging of the battery is compromised. Hence, an uncharged battery poses problems while starting the car.
Malfunctioning of Electrical Components: The electrical components receive power from the alternator, so if you notice that your power window isn’t going up or seats are not heating then this might be due to a faulty alternator.
Dead Battery: This might not be always true, but sometimes a defective alternator can supply excessive voltage to the battery. This might kill the battery for some time or permanently damage it. It is recommended to get your car inspected for other electrical system defects as well if your battery is ending up dead more frequently.
Clinking Sounds: The worn-out bearings and bushes of an alternator can cause growling or rattling noises. Again, this might be caused by other faulty hardware. But you need to make an educated guess in this situation. That if other symptoms are also showing along with these strange sounds then it must be due to a faulty alternator.
Dashboard Warnings: Sometimes dashboard warnings are a blessing. A defective alternator might induce an electrical system failure warning on your dashboard. So, you must get your car inspected immediately if any such warning comes up.
Slow Response of Electrical Components: A bad alternator can cause complete malfunctioning of electrical components or just a delayed response. For example, if you experience a power window going up slower than usual then it is a sign of a bad alternator. Slow windshield wipers and partially heated seats also indicate a similar issue.
Do You Have to Replace the Alternator or You can Fix it?
Normally, it is recommended to get the alternator replaced once its life span is completed. It can be repaired as well, but it isn’t a favored option. Since repair and replacement of an alternator costs almost the same. With the difference of less than $100, you can get a new alternator.
Can You Replace the Alternator by Yourself?
To replace an alternator, you need to disconnect all electrical components like wire, remove all mechanical hardware such as bolts & belts, replace the new alternator, and retrace the dismantling steps. This way you can change a faulty alternator yourself.
It is not that difficult to replace an alternator yourself. If you’re a resourceful person then I say you must go ahead with changing it. You might need the following tools to replace an alternator:
- Belt tensioner
- Screw jack
- Safety gear
Once you have all the tools you can replace the alternator by simply following these steps:
- The first and most critical step is to disconnect the battery cables from the alternator.
- Disconnect the other output wires of the alternator one by one. Keep tagging these wires to avoid confusion while reconnecting.
- Then you pull the serpentine belt off the alternator pulley. This is the hardest step. It can be carried out using a cross wrench.
- Then you cut the bolts that are the last connection between the car and alternator. If these bolts are rusty you can cut them with a grinder. Or open with a wrench after spraying some WD-40.
- Now, you can replace the old alternator with the new one and fasten it to the chassis with bolts
- Inspect for associated components as mentioned in the below section and replace those as per requirement.
- Reconnect the belt, wires, and battery.
- Make sure that the battery is fully charged before making the connection.
Is There Anything Else to Replace when Replacing an Alternator?
Yes, sometimes the following components need to be changed with an alternator replacement.
- Serpentine belt
- Idle roller
- Battery (Not always required replacing)
The serpentine belt, tensioner, and idle rollers are associated with the alternator closely. The serpentine belt is responsible for the transmission of power between engine output and alternator input shaft. The tensioners are there to maintain a certain value of tension in the belt. And the alternator runs on the idle rollers, while the car engine is idle. All these parts are subject to constant wear and need to be replaced with the alternator.
The case of the battery is different. A bad alternator can result in drained battery power but it might not be always true. Any other defect can also cause a dead battery. But once you’ve established that the battery is on the verge of being dead then it might be wiser to get it replaced as well.
Can You Drive with a Bad Alternator?
A bad alternator can lead to a dead battery and the wearing of associated components. This might cause a sudden failure at a bad time. So, you must avoid driving with a bad alternator.
A defective alternator can be quite dangerous. If it is not replaced in time it can kill your new battery. If the voltage regulator of the alternator is not working correctly then it might send more than expected voltage and burn the battery.
Moreover, driving with a bad alternator can cause you a lot of hassle and make driving unpredictable for you. You might experience sudden failures that may bring repairs of hundreds of dollars your way, in addition to the cost of replacing an alternator.
Please be sure that this is not a paid piece, it is a bit of sincere advice not to drive with a bad alternator. You won’t like the consequences!