How Long Can You Drive a Car with Bad Alternator?
With a fully charged battery, you can drive up to 25 miles even if the alternator has gone bad. Therefore, don’t expect your car to drive more than 30 minutes.
How long you can drive also depends on the age of the battery and how much electrical power your vehicle is using. Some cars will stop running even after only five minutes of operation with a defective alternator. Not to mention the damage you may be causing to your battery and your car’s overall health when you drive with a faulty alternator.
As a result, if your alternator malfunctions while driving, we recommend not to drive and get professional help as soon as possible. If you must drive, go to a nearby service station and get your alternator fixed. Here is more information that can help:
The Function of Car Alternators
Table of Contents
- The Function of Car Alternators
- What Happens When the Alternator Goes Bad?
- How to Know If Alternator or Battery Is at Fault?
- Signs of a Bad Alternator
- How Much Does It Cost to Fix an Alternator?
- Final Words
An alternator is a component situated on the front of the engine. Its task is to generate electricity from fuel using alternating currents. An alternator powers your battery, therefore powering the electrical components of your car, starting from the windshield, headlights, radio, AC, and much more!
What Happens When the Alternator Goes Bad?
We first have to identify what has gone wrong with the alternator. It could be either of the following:
- The alternator voltage regulator has failed, or
- Alternator bearing has gone bad
If the Voltage Regulator Goes Bad
You wouldn’t be able to drive very long. The alternator would produce much more voltage than needed. Therefore, it will damage the car’s electrical system, including the battery. As a result, it is not recommended at all to drive with a bad voltage regulator as you are increasing the cost of the repairs, which will be significantly greater than a towing cost.
If the Alternator Bearing Goes Bad
You can still drive a few thousand miles when the bearings have gone out of order. However, it is best to get them repaired as soon as possible. The signs of bearings going bad is you can hear unusual noises from the alternator. The fluctuation of the charge produced by the alternator is also an indication that the bearings are not working correctly.
How to Know If Alternator or Battery Is at Fault?
It is easy to assess the situation wrong when you first encounter it. Sometimes, the battery has failed, but you may be thinking you need to fix the alternator. It can also be the opposite. Here are a few tests to find out which one needs to be handled:
The Battery Test
Start your car first. While the engine is running, open the hood. Then, with proper risk avoidance, detach the negative port from your car’s battery.
After doing so, if your car turns off or stalls, your alternator is at fault. However, if the car keeps running, you are probably having an issue with the battery.
The Headlight Test
Make sure your vehicle faces a wall where you can see the headlight’s light. After that, start your car. Turn on the high beams of your headlight. Make sure you are not in gear and accelerate the car by stepping on the gas.
If you see the flickering of your headlights happening, the alternator may have gone bad. If there’s no flickering, then the alternator is fine, and the reason behind the battery light could be the battery itself.
Signs of a Bad Alternator
Here are some of the common signs of a bad alternator:
Trouble Starting the Car or Stalling
If you start your car and it’s stalling, it can indicate that the spark plug needs more electricity than it’s getting. Moreover, if the car does not start when trying to turn it on, it can also be the fault of a bad alternator.
Keep in mind that these issues can also result from a bad battery.
New models of vehicles have a dedicated warning light on their dashboard that tells you the alternator needs to be checked. However, if you have an older car, it can show battery light instead. Some other cars show texts like “ALT” for alternator issues.
If the warning light is flickering, it may indicate that the issue with the alternator has just started. On the other hand, a steady light means you need to get your car checked up as soon as possible.
If the car makes a whining or growling sound, it is often the alternator’s fault. More specifically, the bearings are bad. If the bearings are not that bad and the sound is barely noticeable, you can drive a thousand more miles. However, the best thing to do is to get it checked out.
If your vehicle’s alternator is faulty, the headlights may start flickering, or other electrical components may stop working or start acting strange. These components are your speedometer, radio, dashboard lights, etc.
How Much Does It Cost to Fix an Alternator?
It’s hard to determine how much you need to spend to fix your faulty alternator without knowing what is causing the issue. But if you need an estimation, be ready to spend anywhere between $500 and $1000. If you are not a professional mechanic, you cannot do the process of fixing or replacing an alternator by yourself.
A faulty alternator can damage other electrical components of your car. As a result, it is better not to drive at all and get professional attention quickly. The most common reason for a faulty alternator is the wearing out of the components. Serpentine belt issues can also lead to alternator problems.
Keep an eye out for any strange symptoms your car faces and resolve them as quickly as possible to prevent alternator issues from happening. A code reader can also be utilized to check the health of the alternator and the battery.