It doesn’t matter if you’ve had a car for a few years or decades; You’ve probably heard of a loose alternator belt.
But how do you know when it’s time to adjust or replace it? Is it even possible on all car models?
In this article, we’ll discuss the symptoms of a loose or faulty alternator belt, its location, and the cost of replacing it. Let’s start with a quick look at the signs to look for:
The most common symptom of a loose alternator belt is a battery warning light on the dash. You can also often hear a belt squeak when the engine is cold. If the headlights flicker or the steering is heavy, it could also be due to a loose seat belt.
The alternator belt not only powers the alternator, but also many other parts of the engine compartment. Therefore, too many things can fail when released.
Here is a more detailed list of the 6 most common symptoms of a loose or faulty alternator belt:
Symptoms of a Loose or Failed Alternator Belt
1. Battery/Alternator Warning Light
Since the alternator or serpentine belt feeds the alternator, of course the alternator will have problems if the belt is loose. Most car models have a battery warning light on the dashboard that illuminates if there is a problem with the charging system.
When the alternator belt is loose, the alternator will not run at its optimum speed and this can cause the charge voltage to drop and the warning light to illuminate.
2. Beeping sound when it’s cold
You’ve probably heard that many older model cars have a very high-pitched noise on cold starts, which will slowly disappear as the engine warms up.
This is mainly due to a loose alternator belt, which becomes smoother and damper in cold weather and causes a high-pitched squeaking noise when slipping on the alternator.
If you hear a high-pitched noise when you start the car for a few seconds, it is definitely time to check your alternator belt. You may also hear a constant high-pitched noise if the belt is always loose.
3. Heavy or shaky steering
As I mentioned earlier, the alternator or serpentine belt drives the alternator and other things like the power steering pump. Some car models have a separate belt for the alternator and power steering pump, but most use the same.
This means that when the alternator belt can also cause the power steering pump to fail, you will recognize it as a jigger or constant heavy steering.
4. Flashing or Dimming Lights
When the alternator charges the car battery, it charges it with approximately 14.5 volts. When the car battery is empty, it usually has about 12-12.5 volts. When the alternator malfunctions due to the alternator belt slipping or coming loose, the tension will also cause peaks and dips.
You can mainly recognize these voltage changes in the headlights or other electronic components. You may see the light darken or brighten, and in some cases you may also see a pulsating light.
5. Sudden Stop
If you’ve driven too far with a loose or slipping alternator belt, things can get so bad that the electronics draw more current than the alternator can produce.
This will bring the car to a complete stop and you will be stranded after the road because there is no chance that you can start it again if the car battery is completely empty.
RELATED: 6 Symptoms of a Bad Alternator
6. Low battery
If the alternator belt is a little loose, it can charge the car battery, but not well enough. This is most noticeable when you try to start the car. If it sounds exhausted at the starter, it could be a sign of a loose alternator belt.
If it gets bad enough, it could even lead to the car battery being completely drained the next time you try to start the car.
Just tighten or replace?
To determine whether you need to replace or tension the alternator belt, look at the belt. If it is cracked or seems very dry, it is definitely time to replace the alternator belt.
When buying a new belt, take care and compare it with your old belt to make sure it is the same length as many car models can have different belt lengths depending on features such as power steering, air conditioning, etc.
When you tighten the new alternator belt, you want to make sure you don’t overtighten it. This leads to a much shorter life and can even damage bearings in parts such as the alternator or power steering pump.
Most newer car models also use an automatic belt tensioner, so belt loosening is rare. However, it can happen and if you have a loose belt on a car with an automatic belt tensioner, you will want to make sure to replace the tensioner while replacing the alternator belt.
Alternator Belt Location
The alternator belt is located at the front of the engine. It is not the same as the front of the car because the engine can be installed on its side in many car models.
However, finding the alternator belt is quite easy for most car models, look for a belt that runs on several wheels and you will most likely find it.
On some car models, the belt can sit quite low in the engine compartment and close to the body, making it difficult to see from above. In this case, you may need to jack up the car and check it from below.
Alternator Belt Replacement Cost
The average alternator belt replacement cost is between $50 and $300 depending on the car model. An alternator belt costs between $20 and $100 and labor costs between $30 and $200 to replace it.
The alternator belt is usually quite cheap, so knowing how to replace and tension it yourself can definitely save you some money.
As I mentioned earlier, most modern car models use an automatic belt tensioner, and if you have a loose belt on one of these car models, you will need to replace the tensioner. These tensioners tend to be a bit more expensive and you can expect to pay between $30 and $150 for a new one.
The alternator can be installed very close to the body, making it very difficult to access. Some car models even require you to raise or lower the engine to get to it.
