Tail Lights not Working but Brake Lights Are? Find Out Why & How To Fix

Safety is of the utmost importance when driving. You need to make sure that your ride is not only in tip-top shape for it to run, but also you need to be mindful of the different safety precautions for your car. Your car lights are just as important as any of the other components in your vehicle.

So why is it that sometimes, your tail lights are not working but brake lights are? In this Garage Chief.com article, we’ll explain why this problem happens and suggest some ways to help you fix this problem for your automobiles. Let’s dive right into it!


The Problem: No Tail Lights but Brake Lights Work


Below is a list of potential problems causing the lack of tail lights despite the fact that the brake lights are still working.


Burnt BULB

no tail lights but brake lights workWe first check on one of the most probable reasons why only your tail light (or tail lights) is not working when your brake lights do, it’s a case of burnt tail bulbs.

Maybe one or both your bulbs have gone bad. Most of the time your tail light bulbs are just like your household bulb (newer uses LED) and you can access them via your trunk or by removing the lenses.

In most cars, you should have an indicator on your dashboard that you have burnt bulbs. But in some cases that you don’t, check the filament wires in your bulb to see if they are still intact, if not, then you’re going to need some replacements.

This should be simple and should not have affected any of your rear light system.

How much does these bulb cost you ask? Around $20 to $200, the entire tail light assembly goes from around $200 to $2000 depending on the quality of the bulbs and some inclusions.

There may be some other expenses like the installation or wires.


Blown FUSE

car fuse blown no tail lightsWhen the fuse is the problem, the circuit for your tail lights would no longer work and naturally, they won’t illuminate.

This sometimes happens when moisture enters your lens through cracks or breaks causing a short circuit and your fuse blows. Each part or component of your car has its own fuse so you need to worry about anything else.

Don’t worry this shouldn’t cost you much. Just get that fuse replaced and you should be up and running.


Check on the WIRING

Very simple and straightforward, visually inspect the rear part of your car especially the wires that leads to your tail lights, see if anything has been cut off or partially damaged. Had some traffic accidents lately? Got hit at the rear part of your car?

It could very well be a power supply issue if the wiring is the culprit. If you find it hard to confirm, don’t worry, it can sometimes be challenging so check-up with your professional car mechanic and see if they can do the tests needed for your vehicle.

Corrosion and animal interference can also be what’s causing the problem, rats just love to nibble on everything they can get their teeth on, so watch out for those too.

It’s important to take note that when it’s already a combination of all the factors we noted above then you may already have a faulty electrical system on your car and may want to talk to your trusted mechanic about it.


Failing RELAY

A relays function is to transfer power from the battery to the lights themselves. One of the rather common reasons why sometimes you have no tail lights but your brake lights work. Check to see maybe your relay is not grounded properly.


Brake light SWITCH

Maybe the lights are working only that they don’t illuminate properly? Sometimes the reason why they don’t light up at all is when the brake light switch that’s supposed to be triggered when you step on your brake pedal is not connecting properly.

We’ve prepared a short DIY test that you can do, to check the reasons we discussed above:

  1. Check if you have voltage to the rear light bulb when stepping on the brake pedal.
  2. Next is to test if you have ground on the light bulb.
  3. If you have both (ground and voltage) then your bulb may be broken.
  4. Test if you have 12 V to the brake pedal switch and if you don’t it may be a broken fuse or damaged wiring.
  5. If you get 12 V to the brake pedal switch and 12 V when pressing on it, you may have a broken brake pedal.
  6. If you get 12 V out of the pedal brake switch but none on the taillights, then it may be a case of bad wiring or there’s corrosion between the pedal switch and the taillights.

Check on the SOCKET

inspection when running lights not working but brake lights doWe’re talking about the socket where your light bulb goes into. Most of the time caused by corrosion due to moisture, when the bulb and your fuse are working fine then it may just simply be the socket that’s not working properly.

Look for any discoloration or bent or broken pins, sometimes white, blue or brown discoloration is an indicator of a faulty socket.

Check your socket’s electrical current with a multi-meter, if there’s no electricity in the pins then you might have just spotted what your problem is.


CONTROL SWITCH

Sometimes it is the switch that’s not working. This switch controls the rest of your lights and it may have gone bad.


Ambient LIGHT SENSOR – When Running Lights Are Not Working But Brake Lights Do

For most modern cars this is the reason why daytime running lights are not working but brake lights do. The ambient light sensor allows the car’s computer to automatically turn the lights on or off according to the levels of light outside.

Naturally, if the sensor gets dirty or is failing, it wouldn’t be able to tell the difference whether it’s bright or dark.



What Else Can You Do?

Whether it’s a broken fuse, bad wiring or a bad and burnt bulb, the common factor that contributes to all of these issues for your tail light is corrosion, most likely because of moisture. And moisture seeps into your vehicle through cracks or breaks through your lenses.

Now that you know how to identify what’s been causing you issues it’s time for a bit of maintenance. There are few simple steps that you could take to fix your car’s lenses.

  • Use a lens repair tape.

    This should only be a temporary fix. You need to be able to clean and dry the area of application. Next is you wipe the area with a lint-free cloth that is wet with alcohol. Let it dry and apply tape. Then, measure the crack and cut the tape slightly larger than the damage. Remove tape then smooth out air bubbles.

  • Use a lens repair RESIN

    If there are broken spots, you might want to use resin. First is you need to cover the damaged area using the repair tape. Mix the resin with the appropriate catalyst and color agent (make sure to wear gloves), pour the resin into a syringe. Squirt resin into the holes or damaged areas. Let it cure for 2 hours. Then, remove tape and then sand the surface as desired to smooth out the repaired area.

  • Use Headlight Restoration Kits

    If you want to restore your headlights or taillights and make it shine like they’re new, there are dedicated headlight restoration kits you can get.

    As we’ve reviewed some of the best ones before, we won’t be repeating ourselves here again, but in a nutshell, those kits usually boast an abrasive technology with a polishing compound to restore your lights to their original state. 


Tail Lights Not Working But Brake Lights Are – The Bottom Line

Costs because of accidents due to lack of vehicle maintenance in the US is about $2 billion and rising. So needless to say, a broken tail light is not something to take lightly or ignore.

This article covered reasons why at times your tail lights are not working but your brake lights are and we hope that we’ve given you some insights on how to get around the situation and to drive safer and care for your vehicle better.


Disclaimers

All product names, logos, and brands are property of their respective owners. All company, product and service names used in this website are for identification purposes only. Use of these names, logos, and brands does not imply endorsement.

It is our policy to make every effort to respect the copyrights of outside parties. If you believe that your copyright has been misused, please provide us with a message stating your position and we will endeavor to correct any misuse immediately.

Some of the links in this post are affiliate links. As an Amazon Associate, we earn from qualifying purchases. This means if you click on the link and purchase the item, we may receive an affiliate commission, at no extra cost to you. This helps us keep this website alive. Learn more here.

Newsletter Updates

Enter your email address below to subscribe to our newsletter

Leave a Reply