Brake Lights not Working, but Tail Lights? How to Fix

Although they are both made up of the same light bulb, brake lights and taillights work in a different way.

Without taillights or brake lights, driving at night can prove dangerous. Problem is, you can't always tell whether your brake or tail lights are working properly.

Both your brake lights and taillights must work. But sometimes there are occasions where one of them works, and the other doesn’t. What is the reason for this?

5 Causes of Brake Lights Don’t Work But Tail Lights Do

Bad light bulbs are the main reason brake lights stop working, but they do work for tail lights. You can also have a bad light bulb, a bad brake switch or blown fuse.

Your vehicle’s taillights are working fine, but the brake lights don’t come on when you press the brakes. It is strange because the brake lights and taillights are connected from one source. One light may shine brighter than another, and the taillights will completely turn off when you brake.

There is always a cause for every problem. And there are solutions. This is an in-depth list that will explain why brake lights don't work and tail lights work.

1. Bad Light Bulbs

For the taillights, LED lights are common in newer cars. However, if your car is older you will need to replace the bulb.

While the tail and brake lights share the same bulb they have two separate circuits. The circuits can be either functional or burned.

Light bulbs are easy to replace and very inexpensive. If you need to verify that the bulbs are still functional, you will be able to either measure them using a multimeter or test them by connecting to an external 12volt power source.

It is unlikely that all three of your brake lights have failed at once, however, if you drive for long periods without paying attention, it could be possible. If the fuse is not installed correctly, it could be that there was a short circuit somewhere.

It is possible that your third brake light may be working but not the brake lights.

2. Bad Brake Light Switch

If your brake lights stop working, a bad brake switch can be a major problem. A small switch is located at the foot of your brake pedal. It informs the controller when you press the pedal, and sends power to your brake lights.

Multimeters can be used to test brake light switches. This will ensure that there is a connection between the release of the brake lever and the press. It may also work vice-versa, depending on what brake switch is used.

3. Broken Fuse Or Fuse Box

The wiring that runs through the fuse box is what supplies electricity to all electronic components in your car. Most modern cars contain two to three fuse boxes. One is located under the hood, while one is usually found below the dashboard.

You need to take out your vehicle’s manual and find out your brake light fuse location. It is possible that the brake light fuse may have been damaged by an electrical surge. Find the right fuse, and replace it by a new one.

Most times, a fuse has blown because of a valid reason. You should ensure that the circuit is not shorted in the wires and connector for the brake light if the fuse blows. In some instances, however, the fuse can burst due to their age.

Make sure to inspect the fuse box simultaneously for water tracks. This can lead to short circuits that could cause a fuse to blow.

4. Connectors and Bad Sockets

The pins connecting the taillights could be corroded. Check for corrosion and rust in the tail light connectors. Apply electrical cleaner to the connectors and reinstall them.

Also, check to see if the connector plug between the taillight and brake light switches is present in your car. In some cases, there is a plug located on the car’s floor, which has been full of water, which caused corrosion.

To locate connector plugs within the vehicle, check your wiring diagram.

Also, there's a possibility that the sockets in which the bulbs are mounted have rust or corrosion. This can be checked for corrosion with an electronic spray.

5. Broken Wire

Sometimes, a damaged wire might be found. The wiring that runs from the front of your vehicle to the rear might be the problem. This could make it difficult for you to identify.

You can measure voltage by pressing the brake pedal while you are at the taillight. Then press the brake lever again at the pedal switch. There is either a short circuit or a bad fuse, but if you don't get voltage at the brake light switch wires there may be a power supply issue.

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