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Signs Of A Bad Car Battery VS Alternator – How to tell if it’s your alternator or your battery? 

Signs Of A Bad Car Battery VS Alternator – How to tell if it’s your alternator or your battery? 

Both your vehicle’s battery and alternator affect the electrical feature’s functionality in your vehicle. Each one of them has its critical role, and if any got bad, the vehicle could not function.


There is a very common misconception about the role of the battery in your vehicle. Many people think that the battery is responsible for making sure that all electrical components in the vehicle are functioning; however, this is not the case.

Your vehicle’s battery is only responsible for providing the starting electrical shock to start the motor. At the same time, your alternator is responsible for converting the mechanical energy produced by the engine to electrical energy used and consumed by all the different electrical components, including the battery.

If you woke up in the morning and tried to start your vehicle but couldn’t, it could be either your battery or your alternator. The question remains, “is it the battery or the alternator?” 

In this article, we will provide you with the list of signs of a bad car battery vs. alternator to help you narrow down the issue and be able to resolve it. We will also provide some answers to the frequently asked questions about the signs of a bad battery or a bad alternator. 

What are the symptoms of a bad alternator? 

 

While the effects of a bad battery and a bad alternator could be similar in some vehicles, there are certain signs that you can track to ensure and confirm it’s coming from the alternator, including: 

 

  • A battery-like warning light on the dashboard 

 

 

Your vehicle’s dashboard has a lot of warning lights that illuminate when there is an internal problem with the car. One of these warning lights looks like a battery. While many people think that this warning light indicates issues with the vehicle’s battery, the actual role of this warning light is to illuminate when there are problems with the vehicle’s alternator.

Therefore come on one of the first ways to confirm a bad alternator is to look for this battery-like warning light. 

 

  • Flickering headlights  

 

 

If you are not able to find a battery life illuminating warning lights on the dashboard, then monitor the behavior of your headlights.

The headlights might flicker, be extremely bright, or dim when there is a problem with your vehicle alternator. This problem will not happen when there is an issue with the battery because the battery does not control or provide any electrical voltage to the headlights.

 

  • The alternator’s voltage is not getting to the electrical components 

 

 

The vehicle alternator generates the required energy needed for all electrical components in your vehicle. Once energy is generated, the alternator sends the electrical voltage to the different components through wires and cables. Over time of use, these wires and cables might crack, tear, or wear. As a result, even if the alternator still works, the electrical components of your vehicle might not function.

To confirm that this is the actual problem, monitor the pattern of your headlights. The headlights would go extremely bright as the alternator tries to produce more power to overcome the resistance of the wires. 

 

  • A broken or loose alternator belt 

 

 

If you were not able to do any of the previous signs, open the hood and check the status of the alternator’s belt. 

The alternator has a belt surrounding it within a specific tension range, as specified by the vehicle’s owner’s manual. If the belt was over tightened or very loose, the alternator will not function properly. Therefore, to confirm that the problem is coming from your alternator, you can open the hood and look for a broken or cracked alternator, if not missing. 

 

  • Weird sounds or smells coming from your alternator 

 

 

As a rule of thumb, if you start hearing any weird noises coming from any part of the vehicle, you should not wait as this indicates an internal problem. While some of these problems might be very easy to be fixed, others might be extremely severe, like a complete engine failure.

Therefore, if you started hearing weird noises coming from your vehicle, whether it’s the alternator or something else, you must take your vehicle to the nearest repair shop and get the problem fixed.

Similar to weird noises, weird smells can also indicate internal problems with your vehicle, including the alternator. Some of the very common weird smells of a bad alternator or electrical fire-like smell or burning rubber-like smell. The electrical fire smell might come from bad wires in your alternator, while the burning rubber might come from a cracked or worn alternator’s belt. 

While these bad smells can indicate issues with the alternator, they can also indicate issues with other internal problems with your vehicle. Therefore, the best way to confirm the issue is to take your vehicle to the mechanic so he can pinpoint the actual problem. 

 

  • A dead battery  

 

 

Yes. If your alternator is bad, it is very likely to have a dead battery. While many other factors might cause the dead battery, if your alternator is not doing its job, it could result in killing you are battery.

 

What are the symptoms of a bad battery? 

 

Since the vehicle battery is responsible for providing the initial electrical shock to start the motor, most battery problems occur right after you try to start your vehicle. 

 

  • Dim dashboard lights 

 

 

One of the easiest things you can do to check for a bad battery is to look at the dashboard battery gauge. On the dashboard, there is a gauge indicating how much charge your battery has. This gage should show some numbers even if the vehicle is not running. 

Another sign you can look for is the dashboard lights; if the dashboard lights are very dim, then this is an indication about something wrong with the battery. 

 

  • Corroded battery 

 

 

Like any other vehicle component, the battery gets old over time of use, and one of the age signs on the battery is corrosion.

If your battery has a lot of corrosion, try to wipe away the corrosion and jumpstart your vehicle. Keep the engine running for a little bit, then turn the vehicle off and try to restart it. If you were not able to restart the vehicle, this indicates that your battery is getting very old, and its the time to replace it. 

 

  • The battery is not able to maintain the charge 

 

 

Another sign of an old battery is that this better you might not be able to maintain, it’s a charge. This is a very common problem with almost all old batteries, And it will not matter as much as you charge it; the battery will be able to maintain the charge. If this is the case, unfortunately, the only solution for you is to take the vehicle to the nearest repair shop and install a new battery. 

 

  • It takes a long time to start the vehicle 

 

 

The last bad battery sign we would like to highlight here is related to the slow vehicle start. If you tried to start your vehicle and notice that it takes the car a little bit longer time than usual to start, then your battery is getting very old, and it’s the time to replace it. 

 

  • Hearing a clicking sound when turning the key  

 

 

When you insert and turn the key in the ignition, you’re asking your vehicle battery to send a current to the electrical components so the vehicle could start. If the battery is bad, it will not be able to send the sufficient electrical power needed to start the vehicle. As a result, the starter will start making a clicking noise that you can hear, indicating a problem with your vehicle’s battery. 

 

  • Vehicle backfires  

 

 

While vehicles backfire could be due to many problems in your vehicle, a bad battery can put the vehicle in the fire! 

This sign of a bad battery cannot be missed. If your battery is failing, it will start making intermittent sparks that result in building up fuel inside The cylinders. If this fuel got ignited, your car might backfire.  

FAQ about Signs Of A bad Car Battery VS Alternator

 

Since there is a lot of confusion about the role of battery versus the role of the alternator in the vehicle, we spared this section to cover the most frequently asked questions about signs of a bad car battery vs. alternator

 

  • Can you jumpstart your car with a bad alternator? 

 

 

Luckily, even if your car has a bad alternator, you can still jump start the car. This is because to start the vehicle; you only need a little bit of electrical shock needed by the motor to start. 

That being said, jump start your vehicle will only give you an additional short period to get to the repair shop not to drive their vehicle for long distances. 

 

  • Can a bad car battery affect the alternator? 

 

 

A bad battery can destroy any perfectly running alternator. The alternator’s job is to ensure that all electrical components of your vehicle have the required electricity to keep them running, including the battery. 

Part of the alternator’s rule is to make sure that the battery is fully recharged. However, the alternator is not designed to recharge a dead battery. If your battery does not maintain the required charge, the alternator will keep trying to get the battery the required voltage. As a result, the alternator can overheat and be self-destroyed. 

 

  • How long will a battery last if the alternator is bad?

 

 

If you have a 12 Volt battery in your vehicle, expected to last between 30 minutes to one hour, assuming that your lights and air condition power off. 

It is important to understand that starting your vehicle requires a lot of voltage. Therefore, you must ensure that your vehicle has more power, and the alternator is functioning properly. 

 

  • Will AutoZone test my alternator? 

 

 

While AutoZone does not replace alternators, they can test the alternator for you if you were able to take it out and bring it to them. 

 

  • Is it safe to drive with a bad alternator? 

 

 

If your alternator is going bad, you must get it replaced or fixed as soon as possible. The severity of a bad alternator on the vehicle differs by vehicles model year; this is because most newer vehicles rely more on the electrical system as some of the safety features might not function if there is an issue with electrical current.

Therefore, you must take a bad alternator very seriously to avoid putting yourself into safety problems. For example, if you are driving at night on a rainy day and your alternator got bad, think about your safety when driving without headlights or windshield wipers. 

 

  • What kind of noise does a bad alternator make? 

 

 

When your alternator goes bad, you will start hearing some grinding or whining noises. This is because the alternator consists of a lot of moving and spinning components, and when any of these components goes bad, you will start hearing this grinding and whining noise. 

 

  • How much does it cost to fix the more alternate? 

 

 

The average price for replacing the alternator with a remanufactured one is about $400. Some automobile experts indicate that replacing the alternator in a domestic car costs between 300 and $500 on both parts and labor. 

When looking for any mechanical replacement or repair asks, keep in mind that the repair costs include the price of the parts and the labor cost. Therefore, if you take your vehicle to a dealership, you will find that the same repair will cost you much more than taking it to the nearest mechanic shop. Similarly, doing the repairs yourself saves you tons of money on labor costs.