Brake And Battery Light On (What It Means and How to Fix It)

Your brake and battery light suddenly illuminating on your dash at the same time can be confusing. In this case, you’ll try to find out what causes this issue and how to deal with it. Luckily, this is what we’re going to discuss in this article.

Brake and battery light come on at the same time when your alternator is malfunctioning and your battery is unable to receive charge. Issues such as a bad battery, faulty voltage regulator, and wiring/connection issues can cause the two lights to illuminate.

In this article, we’ll explore everything you need to know about the brake and battery lights coming on. We’ll discuss all the common causes of this issue and how to fix them to clear off the warning lights.

Brake and battery light on causes:

When the two warning lights come on at the same time, they usually indicate a problem with your battery charging system.

In this section, we are going to discuss the various causes of the brake and battery lights coming on to help you understand what issues you’re dealing with.

Bad alternator

One of the most common causes for the brake and battery light is alternator problems. The battery light specifically will come on when there’s a problem with your car alternator.

If the alternator fails, it’s unable to charge your car battery, resulting in the warning light coming on.

Checking your alternator can be a complex process, so we suggest having a qualified technician inspect it for you.

Dying battery

If your car battery is failing, it will also be unable to hold charge, resulting in both the battery and brake light coming on.

A bad battery cannot supply power to your vehicle’s electrical systems, including the braking system.

If you suspect your battery has died, the best solution is to replace it with a new one.

Faulty voltage regulator

Your car voltage regulator, also known as switch regulator, helps control the voltage produced by alternator.

If this regulator becomes faulty, it can lead to irregular supply of voltage to the battery, making the two warning lights illuminate.

A bad regulator usually also translates to an overloaded or underloaded alternator (or undercharged or overcharged battery). This leads to improper vehicle system operation.

For example, it can affect your braking system circuit, the battery light will come on and the brake light will start flashing.

Wiring issues

Sometimes the two warning lights will illuminate due to connection or wiring issues.

The wires and connectors could be damaged, loose, or corroded, thus disrupting electrical flow within the car’s electrical system.

This triggers the warning lights to come on. A short resulting from faulty wiring can also harm your car’s electrical systems.

Make sure you inspect your battery cables regularly. Also, check that the battery terminals and connections are dry, free of corrosion, clean, and fastened securely.

Bad brake system

If your brake system suffers an electrical malfunction, it will cause the battery and brake lights to come on.

Other malfunctions that may cause the brake warning lights to illuminate include worn-out brake pads, faulty ABS sensor, damaged calipers, etc., all of which can cause the warning lights to come on.

What to do when the brake and battery light comes on

When your brake and battery lights illuminate at the same time, pull over as soon as you find a safe place to do so.

Switch off your car engine and start inspecting your car for a burnt odor from the wiring. A bad alternator usually has a strange smell that you can’t easily miss.

Check the brake fluid level in the master cylinder reservoir. If the fluid has fallen below the minimum mark, you’ll need to top it up to the recommended level.

Keep in mind that low brake fluid could be caused by brake fluid leaks and worn brake pads. Therefore, it is important to inspect your car for these problems as well.

Still under the hood, inspect the battery terminals and cables for any signs of damage, corrosion, or looseness. Check that all your connections are secure and free from any kind of debris.

Fix any loose wiring and clean any corroded terminals using a mixture of water and baking soda and a battery cleaning brush.

If you can’t find any problem after checking your car, take it to your mechanic or auto shop.

The technicians will thoroughly diagnose your car to find out what the underlying problem is and then recommend the necessary repairs to fix the problem.

Why do battery and parking brake lights come on at low RPM?

If your battery and parking brake light come on at low RPM, you would want to check your alternator condition. To be more precise, a decreased alternator output may be the culprit.

When your engine is at lower speeds, the malfunctioning alternator may be unable to supply it with enough electrical power to meet the car demands.

This leads to a decrease in your car battery voltage, causing the battery light to come on. You can confirm by getting a cheap multimeter to test your battery voltage when your car is idle.

The parking brake may also illuminate when the lower voltage affects your brake system sensors.

Once your car starts moving at high RPMs, the alternator output will increase and the warning lights may turn off.

Overall, if your car suffers this problem, have its charging system inspected and the necessary repairs and replacements done to fix the issue.

Why is the brake and battery light on after replacing the alternator?

If your battery and brake warning lights come on after alternator replacement, a few things could be behind this problem.

First, you should check that all the connections around your alternator are secure. Any loose or damaged cables may be preventing adequate electrical power to reach your car battery, activating the two warning lights.

Next, ensure that the fuses have not blown up. In case you come across any blown fuses, replace them with new ones.

You should also check your voltage regulator to see if it works properly. If this device is faulty, it can affect the amount of voltage reaching your battery and activate the two lights.

Another potential cause for this problem is a bad battery. A weak or dying battery will make the battery and brake lights stay on as the charging system struggles to maintain proper voltage levels.

To find out the exact cause behind the warning lights, it is best to have an auto technician perform a thorough inspection of your car.

This should include checking all the alternator wiring and connections, testing voltage alternator, inspecting the fuses, and assessing the battery condition.

Why is the brake and battery light on and off?

In some cases, your brake and battery light may intermittently come on and off. This can also be brought about by a variety of problems.

One such problem is wiring and connection problems. Any loose or corroded wiring and connections will result in intermittent disruption of your car charging system—making the two warning lights come on and off intermittently.

You should check your alternator connections, battery terminals, and grounding points for signs of looseness or corrosion. Tighten and clean them as necessary.

Any damaged connectors, wiring harnesses, or sensors related to your car braking system or battery may also be behind the intermittent warning lights behavior.

If you have a failing alternator or voltage regulator, they can result in an inadequate power supply or irregular voltage output. This will also trigger the two warning lights to come on.

Other potential causes for the two intermittent lights include weak or dying battery and car electrical issues e.g. fault brake sensors and faulty instrument cluster.

What causes the ABS brake and battery light to come on?

The ABS brake and battery lights coming on at the same time usually indicates a problem with your car charging system.

This could be caused by a bad alternator, blown fuse, or loose connection.

However, the brake light may also have been triggered by a malfunctioning ABS system or low brake fluid.

When the two lights illuminate on your dash, it’s a good idea to have a qualified mechanic diagnose your car and find the exact cause causing the two lights to come on.

Is it safe to drive with the brake and battery light on?

It is not safe to drive your car with the brake and battery warning lights on. This combination of warning lights unusually indicates problems with your vehicle’s charging system and braking system.

Car electrical charging systems, in particular, can cause various hazards, including a weakened or drained battery, electrical system malfunctions, overall car performance, and even engine stalling.

A minor charging issue can cause further damage to your car that costs you a lot of money to fix.

A malfunctioning charging system may also stop your car braking system from functioning optimally. This can compromise your ability to brake effectively or maintain proper stability in emergency situations.

If you’re experiencing the brake and battery light on in your vehicle, it could be helpful to check the functionality of your third brake light. In some cases, a malfunctioning third brake light may be the cause. You can learn more about this issue by reading our articles on the Ford Ranger third brake light not working and the GMC Sierra third brake light not working. These articles provide insights into the common causes and potential solutions for a malfunctioning third brake light. Feel free to explore these resources for more information on troubleshooting and resolving this issue.

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Conclusion

Your car brake and battery light coming on your dash at the same time can be caused by a bad alternator, a dead battery, a malfunctioning voltage regulator, and connection or wiring issues. Not to forget that low brake fluid, bad ABS sensor, and worn-out pads can also cause the brake light to come on.

You should never ignore the brake and battery lights coming on at the same time. Take action immediately to find out what issue is making the warning lights appear. Where necessary, seek professional help in fixing your vehicle. Quick action will help prevent potential accidents and avoid further damage that may cost you a lot of money to fix.