When the rear light failure warning light goes off in a car’s dashboard, it indicates an issue with the rear lights.
A blown fuse, faulty wiring, or even a defective bulb are typically the reasons for it.
Driving with malfunctioning rear lights means that other drivers won’t be alerted when you’re braking or turning, and it also decreases your vehicle’s visibility at night.
Moreover, you may get fined by the police for driving with faulty rear lights.
But don’t worry, as we’ve got you covered.
In this article, we’ll discuss the causes and fixes for malfunctioning rear lights. Let’s get started!
What Does Bulb Failure Light Mean?
The rear light failure warning light shows up when the vehicle detects unusual voltages in one or more bulb circuits at the back.
When this happens, one or both rear lights may malfunction or not work at all.
It could happen for several reasons, such as –
- The rear light bulb(s) have gone out
- Electricity is not flowing to the backlight
- Loose bulb or wire connections
- Humidity inside the rear light housing
- Defective sensor giving wrong information
Since the rear lights are a vital component of road-legal vehicles, you should get it resolved immediately after the bulb failure warning light shows up.
Rear Light Failure Warning Light – Causes & Fixes
As mentioned earlier, there are several reasons why rear lights may malfunction. In this section, we’ll discuss the solutions for each of the causes.
The Rear Light Bulb(s) Have Gone Out
A rear light bulb has an average life expectancy of around 5-6 years.
In some vehicles, sensors can detect when a bulb is not functioning optimally, and a warning light is shown, indicating that the bulb(s) have to be replaced.
It can be fixed easily by replacing the worn-out bulb(s) with brand-new ones. Make sure to install them properly, as loose connections may create other problems.
Electricity is not flowing to the backlight
Most electrical issues in vehicles occur due to aging parts or components that weren’t installed properly. The flow of electricity to the rear lights can be affected by these.
Usually, the rear lights are affected when a fuse is blown. You’ll have to locate that in the fuse box and check if it has gone out. If the issue was caused by a blown fuse, replacing it with a new one will solve the problem.
On the other hand, the flow of electricity can also be affected due to faulty wiring or loose connections. This may be a little tricky to diagnose, so you might need help from a professional.
At first, you should try tightening all wired connections to the rear lights and check if the issue is solved. Also, make sure that the bulb isn’t loose.
If you notice faulty/damaged wires, replacing them with new wires will fix the malfunctioning rear lights.
Humidity in the Rear Light Housing
Humidity can often slip underneath the plastic casing of rear lights.
If you can see condensation build-up inside of the housing, it means that the coverings weren’t set properly or they’ve gotten loose.
To fix this, you’ll have to take apart the rear light housing and clean the plastic to remove the condensation.
Once you’re done cleaning, put the light housing back together and set it as tightly as possible, but be careful not to break it.
As an additional measure, you can add sealant around the edges of the light housing to prevent condensation build-up again.
Defective Sensor Giving Wrong Information
Lastly, the issue could lie within the warning system itself.
A faulty sensor can send wrong information to the computer system, due to which the warning light may show up.
On the other hand, the problem may also be within the computer system.
In this case, you’ll need diagnostic tools to figure out what went wrong.
Since the computer system of a vehicle is a sensitive component, it is best to visit a mechanic to get the issue resolved.
Frequently Asked Questions
Which rear light is the brake light?
The rear lights (also known as tail lights) turn on whenever the headlights are switched on in a vehicle. On the other hand, the brake lights turn on whenever pressure is applied to the brake pedal.
In comparison, the brake lights are much brighter than the tail lights.
Are tail lights and brake lights on the same fuse?
It actually depends on the vehicle’s model. Older cars have their brake lights and tail lights running on the same fuse. In recent models, some cars have separate fuses for the brake lights and tail lights.
On the other hand, many vehicles come with dual-filament bulbs that work in different circuits for the tail light and brake light.
Can I drive with my tail lights out?
Without functioning tail lights, other drivers won’t be alerted when you’re braking, and your vehicle’s visibility is significantly affected in dark conditions. In certain states, you could be penalized heavily for driving with tail lights that aren’t working.
Final Thoughts
With all of that being said, you should now know how to diagnose the rear light failure warning light.
Driving with your tail lights out is against the law, and it could potentially lead to an accident as well.
On the bright side, it is easy to repair, and you can get it done by yourself!
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