Why Does Your Brake Light Fuse Keep Blowing Out? (& How To Solve It)

car brake fuse

Brake lights have important safety functions. They can literally be the difference between life and death. So, when your brake light fails, it’s important you replace them as soon as possible. But there are situations where brake light fuses blow up in quick succession. If you are curious about the cause and how to fix it, you’ve come to the right place.

The main reasons why breaking light fuses blow are short circuits and improper fuse replacement. Identifying the cause of the problem is key to finding a definitive fix that will stop the fuses from blowing. 

While fuses are generally inexpensive, regularly replacing them may become a significant expense. Apart from the potential financial implication, routinely replacing brake light fuses can be downright annoying or frustrating. So, if you find yourself in this situation, continue reading to learn how to fix it.

Becoming Familiarized With The Brake Light Fuse

For those not familiar with the brake light fuse, it’s a metal band inside a plastic container. The function of the fuse is to protect the brake lights when the current meant to flow to it is too high. Instead of the brake light becoming damaged due to high current, the metal band inside the fuse will instead melt and this cuts power to the brake lights which won’t work until the fuse is replaced.

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Fuses are usually placed in a panel inside the cabin of vehicles or under the hood. Since a car has several electrical components, it has several fuses protecting the components. If you want to inspect your brake light fuse to check if it’s the reason your brake lights aren’t working, you’ll first need to figure out the fuse protecting the brake lights. 

To identify the brake light fuse, open the areas where fuses are located (described above). The function of each fuse is written on their panels and you just have to look around until you find the brake light switch. For an easier method, consult the owner’s manual or find a digital copy online. You can also look up the model or make of your vehicle online to find a diagram that highlights the fuses including the brake light fuse.  

Why Does My Brake Light Fuse Keep Blowing?

Below are the common reasons why your brake light fuse keeps blowing:

Short Circuit

This is by far the most common reason why fuses keep blowing. A short circuit occurs when there’s a poor connection between two electrical conductors. So, instead of the wiring overheating, the fuse will blow. Short circuit may occur due to the following:

• When the wire insulation becomes exposed, it can make contact with metal frames or other wires. This results in intermittent shorts and may cause your brake light fuse to blow. 

• Malfunctioning Brake Lights: The brake light bulbs can be the reason why their fuses keep blowing. The brake bulb holder may have corroded or rusted over time making the bulbs draw more current than they need. And the higher current can result in a blown fuse. 

• Fuses are supposed to be protected from water. There might be a leak somewhere in the fuse that allows water to come in contact with the wiring and connection points. When this happens, the electrical conductors may get wet, eventually malfunction, and blow. 

Improper Fuse Replacement

Another reason why your fuse may keep blowing up is if you are replacing blown fuses with one of higher amperage. The owner’s manual will tell you the correct average rating of each fuse in your vehicle and it’s important to install fuses that meet this specification.

Failure to do this will result in a fuse that keeps blowing. If you don’t know the correct amperage of your car’s fuses, have a chat with your mechanic to be sure you install the right fuse.

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Other Reasons Why Your Brake Lights May Not Be Working

car fuses

Your brake lights may also not work apart from the reasons discussed above. Other reasons for nonfunctional brake lights include:

Worn Out Wiring

Sometimes, a broken wire may be the reason why the brake lights aren’t working. When there’s a break in the electrical connection, the current can’t reach the bulbs and they won’t work. You may need a wiring diagram to trace the broken wires when you’ve replaced the fuse or bulb and the brake light is still not working. 

Control Switch Failure

While the brake light control switch rarely malfunctions, it may be a good idea to check them out when other options have been explored without success. A faulty control switch will result in brake lights that won’t light up. 

How Do You Fix A Fuse That Keeps Blowing?

When your brake light fuse keeps blowing repeatedly, it’s time to get a mechanic to inspect the electrical systems including the light bulbs. This helps reveal the cause of the problem and provides a definitive fix.

If the light bulbs or the metal panels that connect them are the problem, they will have to be replaced alongside a new fuse. If it’s worn out wiring or improper fuse replacement, the proper solution will be applied. The key is to correctly identify the problem as the solution depends on the reason why the bulb keeps blowing. 

Driving With Malfunctioning Brake Lights

While your car will still work properly without brake lights, it’s important you don’t drive any vehicle that has faulty brake lights. Remember that the brake lights are there for safety purposes and they will signal other vehicles that you are slowing down or about to come to a stop. 

In many countries, it’s an offense to drive with malfunctioning tail lights. The police or other traffic officials may stop you and charge you. Depending on your location, you may be required to pay a fine, attend a mandated traffic safety course, or have penalty points on your license. 

The fine can be very heavy in some countries in a bid to make people comply with traffic regulations. So, you are better off complying with the rules to save yourself stress and money.

Author

  • Vedran

    Vedran, is a long-time expert in the field of automotive repair. After completing school for car mechanics, Vedran has amassed years of experience working on all types of vehicles. In addition to running Vedran’s own successful car repair service, Vedran is passionate about sharing his knowledge with others and helping people take better care of their cars.