Car Brake Light And Battery Light On – Causes

Car Brake Light And Battery Light On – Causes

When your car brake and battery lights turn on, it often indicates a problem.

But what exactly can cause the brake light and battery warning light to illuminate, and what should you do?

Car Brake Light and Battery Light On

Well, in this article, we will discuss everything you need to know about car brake lights and battery lights popping up.

We’ll explore what causes car brake and battery lights to turn and the potential solutions.

Reasons Why Brake Light Turns On By Itself

Car brake lights turn on and show on your dashboard because of different causes. Some of these causes are easy to fix without requiring you to call a car mechanic.

For others, you will require to hire a car mechanic. It is to avoid making the problem even more complicated because they are hard to fix.

We’ve compiled some of the common causes that make the brake light turn on by itself and illuminate on the dashboard:

Parking Brake Not Completely Disengaged

An engaged parking brake is the most popular reason that causes a car brake light to come on.

A car brake light will turn on when someone forgets or fails to completely disengage a car’s parking brake.

The only solution to fix a car brake light is to release the parking brake lever.

If you’ve done this and it doesn’t turn off the light, the parking brakes have malfunctioned, or the lever is broken.

You need to get a professional car mechanic to fix your car if the latter is the case.

Low Level Or Leaking Brake Fluid

Low braking fluid is another reason that causes car brake light to come on and several other braking problems.

Besides the low level caused by the vehicle consuming the brake fluid, brake fluid leakage is another cause.

You can quickly identify the main reason why your car brake light turned on and became illuminated on the dashboard.

In this case, the braking system may need brake fluid flush or repair. As such, you must learn how to check your brake fluid.

It will help you to avoid catastrophic brake failure. We recommend turning off the car and getting an auto mechanic for the leakage.

Never attempt to fix the problem yourself if you have no auto mechanics knowledge. You risk increasing the problem’s complexity and severity of the damage by trying to do so.

Brake Pads Have Become Worn Out

Worn-out brake pads can trigger car brake lights turning on. These worn-out brake pads lead to a drop in brake fluid level.

The drop in the brake fluid level forces caliper pistons to go much deeper to contact the rotor.

The car brake light can also be forced to turn on when the sensor wire contacts the rotor. It causes the brake pad warning light or the car brake light to turn on.

The solution to resolve car brake light turning on is to replace worn-out brake pads with new ones. It is something you can easily do yourself using the appropriate tools.

A Malfunctioned Antilock Brake System

Sometimes, car brake lights can turn on if there is a problem involving the car’s antilock brake system.

Among the causes of this problem are electrical malfunction and a wheel speed sensor that has become dirty.

The car brake light turning on caused by malfunctioned antilock brake system is best handled by a mechanic.

We recommend consulting a professional auto professional to determine the extent of the problem and the best way to solve it.

A Faulty/Burnt Out Brake Light Bulb

Another cause a car brake light to turn on is a faulty or burnt-out rear brake light bulb. When the rear brake light bulb gets burnt, it can trigger the car brake light to turn on.

Another scenario that can turn a brake light on is when rear brake lights dim. For drivers who may not be aware of the status of the rear car brake light, this is a good thing.

When the car brake warning light turns on, it helps drivers avoid rear-end accidents.

The solution to this cause of car brake light turning on is to have the rear brake light bulb swapped. Although it is possible to do this yourself, we recommend getting a mechanic.

This recommendation is based on knowing that every car has a unique light bulb and bulb socket.

Car Brake Light and Battery Light On Causes & Solutions

Reasons Why Battery Light Turns On By Itself

Various reasons can cause a car battery to turn on by itself. When a battery light illuminates the dashboard, it indicates a car battery charging problem.

The battery light on your car dashboard usually turn on because of one or more of the following causes:

Bad Or Dead Battery

Car battery light can turn on and illuminate on the dashboard to warn you about a dead or bad battery.

It occurs after your car battery has aged and its electrodes break, generating decreased voltage.

A Malfunctioning Or Faulty Alternator

If your car has a malfunctioning alternator, it will generate a voltage below optimal.

It will affect the proper functioning of the car battery. It will cause the car battery light to turn on.

Broken Alternator Belt

Another reason that causes your car battery to turn on is a broken alternator belt.

An alternator belt breaks with repeated working that causes cracks to develop over time before eventually breaking down.

When this happens, the car battery doesn’t get charged. It causes the battery warning light to illuminate your dashboard.

Corroded Battery Terminal

Since a car battery gets power via battery terminals, a corroded battery terminal can cause poor conductivity of electricity.

The result is a battery charging problem which can cause a car battery warning light to turn on.

Faulty Battery Cable

A faulty battery cable can cause a car battery light to turn on when it interrupts the flow of electricity.

It can also activate the battery light if the cable is not fitted correctly around the battery terminal.

Wiring Problems

Sometimes a battery light turns on because wires responsible for supplying power to the charging system have broken or have disconnected.

As such, the battery warning light will turn on to indicate charging issues within the charging system and electrical circuit.

Accessory Overload

If many accessories draw power from the alternator that also charges the battery, the battery won’t charge properly.

If this persists, the battery’s power level will deplete faster, causing the battery warning light to turn on.

How To Resolve Car Battery Light Turning On By Itself

Turn Off All Unnecessary Car Accessories

Immediately your car battery light turns on, and the engine may go off anytime because the battery is not charging.

You need to turn off all unnecessary electrical accessories in your car quickly.

It includes unplugging your phone from the charger, turning off the HVAC system radio, and disabling the power window.

Check Your Car Battery

Check the battery for signs of damage or corrosion on the terminals. Clean the corrosion and correctly secure the clamps on the battery terminal.

Check The Alternator

Check the alternator for any missing components or loose connections. Tighten any loose connection you find correctly.

Get A Professional Auto Mechanic

Immediately you see a car battery light turn on, the best solution we recommend is to seek professional help.

Park the car safely and call a professional mechanic to diagnose and fix the problem.


Many reasons can cause your car brake and battery light to turn on by themselves.

When any of these lights are illuminated on your car dashboard, immediately identify what’s causing the problem.

This article has discussed some of the causes and solutions for car brake and battery lights turning on. If you can, fix the problem before it becomes more complicated.

If the problem is too complicated for you to fix, contact an expert mechanic to diagnose and fix it properly.