Tail Lights Not Working? Here’s Why

Every car should have tail lights since they are a crucial safety component. These are essential for nighttime, dusk, and inclement weather like rain and snow. Your car’s rear should be well-lit thanks to your taillights. These typically come on when you turn on the switch, illuminating your headlights.

Several more recent models have an automated sensor that activates them when it notices a reduction in ambient brightness. Much like any other component of an automobile, the failure of the tail lights poses a severe threat to public safety.

Due to the lack of rear lights, this is risky for other motorists who may not notice your car, but it may also result in a ticket from the police or a failure of your state’s registration inspection procedure.

Common Causes for Tail Lights Not Working, But Brake Lights Are

1.     Tattered wiring

There is likely a damaged or broken wire somewhere along the line if no electrical current is getting to the socket and the fuses have been checked out as OK. Get a wiring schematic now, and visually check the wires along the tail light circuit for frayed or cracked insulation.

Verify the body grounds that exit this circuit as well. Electricity supply to the sockets will also fail if the ground wire is filthy, brittle, or broken.

2.     Failed Control Switch

The switch that operates the tail lights is another factor in their failure to illuminate. Once everything else has been examined and found to be in good working order, the dash’s headlight switch should also be checked. This switch often illuminates the parking lights, taillights, and headlights.

This switch may have failed if the tail light circuit’s other components were functioning correctly. You can remove it from the dashboard and examine it with a multimeter to confirm that it has failed.

An auto mechanic repairs the wiring of the car.

3.     Unclean or Poor Ambient Light Sensor

In the dashboard of many contemporary vehicles is an ambient light sensor. Of how bright or dark it is outside, the computer in the car can automatically turn the headlights and taillights on and off. On modern automobiles, some people additionally switch off the daytime running lights.

This is the likely cause if your brake lights turn on, but your parking lights and headlights do not. This sensor can no longer determine whether it is day or night outdoors and may not turn on the lights. Manually turning the headlight switch to the on position could be easily tested and would affect both the headlights and tail lights.

4.     Connector Failure

The socket where the light bulb is inserted can malfunction occasionally. Typically, corrosion—brought on by moisture entering the socket—is to blame. Yet, a bad connection of the wires in the back could also lead to failure. If the bulb and fuse are in good shape, examine the socket’s condition while still in it.

Search for any color changes, such as white, blue, or brown, as well as bent or broken pins. At this stage, it’s a good idea to use a multimeter at the socket to verify the electrical current. No energy flowing to the pins indicates an electrical line failure higher up.

5.     Defective tail light bulbs

The tail lamp bulbs should be the next thing you check if the fuses within the cab and under the hood pass inspection. Although some vehicles have an access panel where you may reach in and twist the bulb out of the lens, usually, this involves removing the tail light cover.

A defective bulb should be removed from the socket it is inserted into and thoroughly inspected for damage to the filament. The wire that produces light inside the bulb is called a filament. If the filament breaks, there will be no illumination, and a new bulb needs to be installed.

6.     Defective tail light fuse

A fuse is just a metal band enclosed in a plastic bag intended to blow when the current flowing through it rises to a certain level. By doing this, the electrical system’s other components are shielded from harm. In a car, fuses are often located in two places. One is a fuse panel located inside the car’s cabin.

Close up shot of car fuse box with removed cap.

Usually, this is on the front passenger side, concealed by a plastic panel under the dash. It may be found in the glove compartment of some vehicles or on the side of the dashboard when the passenger side door is fully opened.

The main fuse box under the hood is the second most frequent location to find fuses. It is a big black box with numerous wires attached to it. Once the top cover has been removed, you can reach the fuses within, including a turn signal and headlamp relay.

The functions of each fuse, whose cover you removed to expose them, should be listed on it. Each fuse regulates a distinct electrical component. If not, the owner’s handbook or an online search for a year, make, and model-specific schematic can be used to identify them.

Once the fuse for your tail lights has been located, you may test it with a fuse tester, which will light up if the fuse is functioning correctly. Replace the fuse with the same size and amperage if it doesn’t light up. A visual break in the metal wire inside a faulty fuse can be seen with some fuses.

How To Fix It

There are times when tail lights need to be maintained. Sometimes, they quit working or burn out and require a replacement bulb. Someone trying to solve the issue can become frustrated. Fortunately, there are a few common problems that, with the proper knowledge, can be easily fixed.

You may select the broken tail lights and get them working again using the techniques below. Fortunately, any replacements for the below-mentioned issues are easily accessible and don’t need significant investment.

1.     Replace the lightbulbs

One of the most prevalent and straightforward issues to fix is burned-out bulbs. There is no doubt that these bulbs need to be replaced. Any automobile outlet has new bulbs on sale. Just make sure the size and produce are suitable for your car.

If you purchase an inappropriate bulb for the type of car you own, the lights will either not work at all or work just briefly before burning out. You may then remove the lens cover by using a screwdriver to pry it loose. Remember to place the body away from your working area gently. Use the same screws to attach the surface once you’re done.

As soon as the bulb is visible, grab it and spin it in the opposite direction until you feel it relax. Then you may take it out. The replacement bulb should be inserted into the area and rotated until securely fastened.

Once the brakes are applied, test whether the new bulb works in the tail lights. If the tail light covers are working, you can leave them alone. If the issue still exists, a new fuse can be the answer. This is covered in more detail below.

2.     Fuse replacement

Find the control panel inside the vehicle. You can find all of the necessary fuses here. Find the “tail lights” one and relocate it from its position. Any repair shop should be able to provide you with a replacement fuse; make sure you get the right one for your vehicle.

Until you hear a click after installing the replacement fuse. One more time, look at the brake lights. Let’s hope the troubleshooting steps described above have made your car’s tail lights functional.

3.     Battery energy

Make sure that the battery is releasing energy, as well. Although it may seem obvious, damaged tail lights are one of the most common causes of this problem. You can use your horn to check the electricity’s flow. It’s time to sound the horn.

It means the battery is not the problem if it makes noise. You might go on to the next potential source of the issue once you have ruled out the first one.

Conclusion

Finding an electrical problem can be challenging and frustrating overall. Fortunately, tail light bulbs often operate on their isolated circuit, making it quite simple to identify issues.

The brake lights work on a separate line of circuitry from the tail lights, so even while all of these faults prevent the brake lights from turning on when the pedal is depressed, the tail lights will still not function.

For their safety and the protection of others, drivers should fix their broken tail lights as soon as they become aware of the issue.

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About Brock Rangel

Hi, I am Brock, and I am the lead editor/photographer for TheCarColony. I have been a mechanic for over 14 years now, and I am here to spread my car knowledge across the web!