5 Reasons Why Tail Lights Stay on When the Car is Off

You get to your destination and park your car. As you are walking away, you notice your tail lights are still on, even though the car isn’t running. By now, you are aggravated that you have to go back to the car. How does this happen and what can you do?

How Do Tail Lights Work?

Tail lights are turned on when you turn on your headlights. This is known as working on a relay. Taillights and headlights are wired to the same switch. Should you have automatic lights, your tail lights will turn on whenever your headlights turn on. Tail lights are wired directly to the battery in your vehicle. 

Types of Tail Lights

There are various types of tail lights available for your vehicle. 

LED lights are trendy right now. These are a favorite choice for tail lights. LED lights utilize a lower amount of energy and last longer than classic tail lights. 

Halogen lights are the most common type of tail light. These are what comes standard on most types of cars. 

Xenon lights are another kind of tail light. These are very strong, bright, and have a higher intensity compared to the other lights. An electrical arc is used in Xenon lights whereas others use a filament.

Reasons Why Tail Lights Stay On

If your tail lights are staying on after you turn off your car, there could be a few reasons why. 

Broken Brake Light Stopper or Switch

There is a chance that you have a broken brake light stopper or switch. Lots of vehicles have a stopper at the top of the brake switch. It will disengage when the brake pedal is stationary.

If this plastic stopper breaks or moves, it can leave the switch engaged. If this stopper or switch is defective, your lights receive the wrong message and will stay on. 

This is easy to check. Find the switch located at the top of the brake pedal. This will be underneath the dash.

Have another individual stand behind the car. Look at the stopper on the pedal. Is it on the pedal? Apply pressure to the brake pedal to have contact to the switch. Then push down on the button on the brake light switch. 

If doing this doesn’t shut off the brake lights, or the button neglects to be pushed down completely, the switch may need to be changed.

A short-term quick fix to this issue is to unhook the battery. In order to access it later, this solution is not advised if the hood latch is electric and not cable-operated. 

If the brake lights turn off because of this, the stopper is most likely not attracting the switch. Switch out the stopper with a new one.

For a short-term quick fix, you can tape an object with similar width to the stopper such as a coin. This should disconnect the switch until the stopper is switched. 

Bad Wiring Harness

Another reason why your tail lights stay on when the car is turned off is due to a bad wiring harness. Faulty wiring can easily make this occur.

You can fix this yourself by first cutting the old connector off. Strip and twist the wires, then connect the new switch with a splice connector. 

Faulty Trailer Light Plug-In

If you have corroded trailer plug-in lights, your tail lights may stay on. First, check to determine no other lights on the tail light housing stay on.

Next, disconnect the switch if your trailer has one. Should the tail lights turn off, chances are the switch is faulty. You will then need to replace the light plug assembly. 

Corrosion or Debris

Corrosion or debris can cause issues in a car when the debris piles up. Even a tiny amount of dirt can cause issues. Simply check to make certain there is not a debris build-up.

If found, remove the build-up and double-check to make sure the tail lights have turned off. 

Wrong Lights Installed

While this may sound funny, installing the wrong lights could cause your lights to stay on. This is not a common issue, but could still take place. 

There are two different kinds of light bulbs. One has one circuit and the other has two circuits. The circuit shorts out if you use the wrong type of light bulb (installing one circuit into a two circuit). This will cause the lights to come on and stay on. 

Tail Lights Vs. Brake Lights

You will want to make sure that it is your tail lights and not really your brake lights.  Each of these lights have different functions.

However, many individuals will use them interchangeably. If you are uncertain what the difference is, here are a few differences. 

Tail lights glow red when the headlights of a car are turned on. Many states have restricted the tail light color to only being red. When they are activated, they have a brighter appearance than when the vehicle is in motion. 

Their purpose is to create visibility for drivers around you when it is dark or there is adverse weather. Tail lights may also act as parking lights depending on the make and model of your car. 

Tail light issues are generally easy and inexpensive to fix. It may just be a matter of replacing a bulb or wiping down the light so it is more visible. If your car has been hit from behind, it is not uncommon for the tail lights to become broken or damaged. 

Brake lights are located on the tail light. These alert drivers that you are slowing down. Brake lights are critical to have working so situations are safe. 

They are generally brighter than tail lights. These lights will need to be replaced or fixed at some point in their lifespan. 

Both tail lights and brake lights should be inspected on a regular basis. 

In Conclusion

If you notice your tail lights stay on when you turn your car off, you should have this taken care of right away. If you are not able to fix the tail lights, contact your dealership or a mechanic and have them take a peek at it. 

  • Eric Williams

    I'm the founder of Daily Car Tips. I wrote articles in the automotive industry for more than 10 years, published in USA and Europe. I love sharing my knowledge and insights with fellow enthusiasts. Join me on this journey as we explore the exciting world of cars together!