How to Tell When You Have a Bad Alternator or Battery

How to Tell When You Have a Bad Alternator or Battery

Do you have a problem with your car acting up? Do you know if it’s a bad alternator or a bad battery? There are tell-tale signs that will help diagnose the issue. In this blog post, we will discuss what those signs are and how to fix them!

You try to switch on your car, but it won’t start. There are two problems that can cause this. The first is the battery and the second is the alternator.

But how do you know who did it? You need to know what caused the problem before you can fix it. So how do you tell if it’s the battery or the alternator?

Here are signs that will help you decide:

  • If your car is making a loud noise when you try to start it, it might be the alternator. Alternators usually make a whining noise when they start going bad.
  • If your car is turning over slowly or not at all, it might be the battery. Batteries tend to lose power as they age.
  • If your headlights get dimmer when you turn on other electrical devices, it might be the alternator. The alternator charges and maintains the battery while driving. So, if there’s something wrong with the alternator, the battery won’t get charged properly.

The Batteries Are to Blame:

Whenever you have an issue with your car and it isn’t working, you should first look at the battery. The life expectancy of your car battery is usually between 3-5 years or so. Cars have inbuilt diagnostic systems. But it is not good to always rely on them when they say what the problem with the vehicle is. You should look at other things like what you see and feel.

Sometimes your car won’t start. You can try to start it again by plugging the vehicle into power using a jump start.

If you have a malfunctioning or dead battery, then you can use jumper cables to start your car. If someone does not have jumper cables on them, then you can ask a friend for help. And if they do not have the cables on them, then contact AAA or another similar company who can help out.

You have a terrible car battery if the jump start doesn’t work. You need to find your way to get your battery replaced.

If you see that your battery light is on while you are driving, then you know that it’s terrible. This is a peculiar sign. If this happens, then don’t wait until the battery dies before doing something about it!

A lousy car battery will make a clicking noise when you try to start it. A dead battery won’t make any sound at all.

Don’t forget to check the battery for split wires or corrosion.

A Faulty Alternator Is to Blame:

If the battery is working fine and yet your car won’t start, then it must be a problem with the alternator.

An illuminated dashboard light can mean you have a problem with your car’s charging system. One way to check if the alternator is working is to disconnect the positive terminal on your battery. If the vehicle stops running, then you probably have a lousy alternator.

If the dash lights are too bright and then go dim, you have a bad alternator. The battery starts the car and lights, but it relies on the alternator to keep working when you are driving. When the lights come on but don’t stay bright, then something is wrong with the battery.

Besides lights that are too dark, a failed alternator can also make strange sounds when you try to use the car stereo.

Frequently Asked Questions 

When the repairs are delayed, what happens?

A bad alternator can cause a bad battery because the battery starts the car, and then the alternator takes over.

So when the alternator is bad, your car will run on its battery. The battery is not made to work for long periods of time, so it will wear out. Eventually, your car will stop working because the battery can’t do everything.

A car has a battery that needs to work all the time. If it goes bad, people will not be able to start their car. They need a new battery or alternator. It is good to have a mechanic check your car so you know if anything needs fixing or replacing before it goes out, and you cannot drive your vehicle anymore.

What are the warning signs of a bad alternator?

The lights might be dim or too bright. The battery might be dead. Accessories like the air conditioner or radio might not work well or work at all. It can be hard to start the car, and sometimes it will stall out. It can make weird noises like growling, whining, or clicking sounds. There may also be a smell of burning rubber, which means there is something wrong with your wires. If you see these things happening with your car, then you need to get it fixed right away before something terrible happens!

How can I test my alternator?

Just like checking your car’s oil pressure, there are accessible videos online that teach you to test the alternator. Multimeters measure electricity and how much is there. It is used to test electrical circuits as well as to measure voltage, current (amperage), resistance, continuity, and other parameters. Use a multimeter to test your alternator. Multimeters have two cables: black and red. Put the black cable at the negative terminal of your alternator and put the red cable on the positive terminal of your alternator to get an ideal reading that is between 12 volts or higher, but not more than 15 volts, in order for it to work well.

Can you jumpstart a car with a bad alternator?

No matter how bad your alternator is, you can make it work by jumping-start the car. The car will keep running for some time with the battery, but not for very long.

How much does it cost to replace alternator?

When your car has electrical problems, it means you need to replace the alternator. You will spend about $500-$1,000 for a new one, and you need to pay someone else to do the work.

Can a bad alternator drain a battery?

A car part called an alternator would keep charging while the car is off. This can drain the battery, so it won’t start.

How long does it take for a bad alternator to drain a battery?

In this situation, the car will run for a maximum of 30 minutes if you are lucky and can get up to two hours. Note: In case you have to start the car without an alternator, keep going once you’re going because turning it off flattens the battery down.

What does a dead alternator sound like?

If you hear a rattling or grinding sound when you are driving, it may be because your alternator is loose. If you hear a high whine, it could mean that your alternator is not working and not giving power to the car.

What sound does a bad alternator make?

A noise that you can hear when your car’s alternator is not working will be a high-pitched whine. You’ll hear the whining noise get higher in pitch when the RPMs increase.