Brake Lights Not Working But Tail Lights Are, and Vice-Versa

When it comes to automotive lighting, most people get confused by the terms "brake light" and "taillight". Certain queries come around in their mind regarding these lights like, are both the lights the same? Do they have any common connections? Actually, these are completely different lights and their purpose too.

Both the brake lights and the taillights are crucial for road safety. To distinguish their differences, you must first know how they work.

Both these lights are located on the rear side of a vehicle. The brake lights are connected to the brake system of the vehicle. The bulbs light as the brake is applied. In the case of tail lights, it is connected to the headlights. The brightness of the tail lights is low compared to the brightness of the brake lights.

If any of them don't work, other drivers behind you won't see if you're moving or not. It can cause serious accidents, especially on dark streets or during heavy rain and snow. The cops are also very strict with this and will flag you if your lights are not functioning.

Read on to find some reasons why your brake and tail lights might not be on the same page performance-wise. Interested in graphical data? Head over to our infographic poster below.

Reasons Why Brake Lights Not Working When Tail Lights are:

There’s nothing more frustrating than realizing that your brake lights are not working, but your tail lights are. You would think that they would be dependent upon each other, but oftentimes, that is not the case. Below listed are the most common reasons behind this scenario.

  • Malfunctioning light bulbs—simply put, your brake light bulbs may not be working like they should, which is causing a problem with your car’s lighting system.
  • Fuse box and light switch problems—another reason why your brake lights aren’t working is the wiring. The wires connecting from the fuse box panel to the brake light switch could be damaged or loose. Loose wire between the light bulb socket and fuse box might be causing the trouble you’re experiencing.
  • Faulty electrical ground—another culprit of this conundrum could be that the electrical ground wiring is damaged, corroded, or loose.
  • Wiring—loose, frayed, or otherwise faulty wiring can cause plenty of brake light issues.
    • Check your connection to determine if the bulb light housing is bad.
    • If so, these parts may need to be replaced before causing further problems down the road.
  • Turn Signal Switch—in some cars and trucks, the brake light circuit is connected to the turn signal circuit with a single wire.
    • If this is the case for your vehicle, any issues with the turn signal connection can result in a malfunctioning brake light.

Reasons Why Tail Lights not Working When Brake Lights are:

What if you’re experiencing the above described situation in reverse? Let’s explore some instances that might be causing your tail lights to cease proper functioning despite your brake lights working correctly.

  • Faulty fuse—when troubleshooting this issue, the first piece of professional advice you’ll usually receive is to check the tail light fuse. Often, a bad fuse is to blame.
  • Wiring—once again, wiring issues are key to pinpointing this problem. Any loose, frayed, damaged, or otherwise faulty wiring in your tail light system will usually not affect your brake lights because they are powered by different wiring systems.
  • Bad bulbs—another possibility is that you’ve got a bad bulb (or bulbs) on your hand. If the filament inside the bulb is broken, you’ll likely experience this problem.

Best Brake Lights to Buy

If you’re in the market for some new brake lights, look no further than these top picks from the automotive lighting pros at Underground Lighting.

  • 7443 Red Brake Lights —this top customer choice is a direct replacement bulb for rear brake lights and turn signals.
    • Ultra-bright, long-lasting bulbs feature a cooling fan to prevent overheating, as well as no hyper-flashing or error codes to cause worry.
  • 3157 Red Brake Lights —another fan favorite, this brilliant, bright and long-lasting bulb also boasts a cooling fan and no worrisome hyper-flashing or error codes.
    • The deep red LED light covers 360 degrees, promising maximum output.

Ready to revamp your car or truck’s brake lights, tail lights, and more?
Head on over to and let the pros at Underground Lighting help you make the perfect pick for all of your vehicle lighting needs.

 Check our infographic poster:

Brake Lights Not Working But Tail Lights Are, and Vice-Versa