8 Reasons Why Your Tail Lights Don’t Work But Brake Lights Do

Just like every other part on a car, tail lights can stop working, causing a major safety concern. Not only is this dangerous for others on the road, but you can also get a ticket from the police, or fail your state’s inspection process for registration.

But what does it mean when your brake lights work and at the same time, your tail lamps don’t?

tail lights don't work but brake lights do

See Also: Brake Lights Won’t Turn Off?

Common Causes for Tail Lights That Don’t Work But Brake Lights Do

#1 – Bad Tail Light Fuse

car fuse box

The first thing to check when facing an inoperational electrical component, especially when it comes to lighting, is the fuse.

A fuse is basically a metal band inside a plastic container designed to break when the current flowing through it becomes too high. This protects other parts of the electrical system from becoming damaged.

There are generally two areas that contain fuses in a car.

  • One is a fuse panel inside the cabin of the vehicle. This is normally in the front driver or passenger side, behind a plastic panel underneath the dash. In certain cars, it can be found in the glove box or on the side of the dash with the passenger side door opened all the way.
  • The second common area to find fuses is in the main fuse box under the hood. It’s a big black box that has a lot of wires attached to it. Once you take the cover off the top of it, you can access the fuses inside including a turn signal and headlamp relay.

Each fuse controls a different electrical component, and their jobs should be listed on the covering you removed to access the fuses. If not, they can be identified by using the owner’s manual, or by looking up a year, make, model specific diagram online.

Once the fuse that controls your tail lights is identified, it can be tested using a fuse tester, which will light up if the fuse is good. If it doesn’t light up, the fuse should be replaced with one of the same size and amperage. On certain fuses, you can visually see a break in the metal wire inside a bad fuse.

Read Also: 3 Signs of a Bad Flasher Relay

#2 – Bad Tail Light Bulbs

bad-tail-lamp-bulb

If the fuses under the hood and inside the cab check out fine, the next culprit to look at are the tail lamp bulbs themselves. This generally involves removing the tail light cover, although some cars have an access panel where you can reach in and twist the bulb out of the lens.

The best way to identify a bad bulb is to remove it from the socket it is plugged into, and closely inspect the filament. The filament is the wire inside the bulb that creates the illumination. A broken filament means no illumination and you will need to replace it with a new bulb.

Already changed the light bulb with a new one and it’s still not working? Read on.

Related: 5 Causes of a Turn Signal Blinking Too Fast

#3 – Socket Failure

bad bulb socket

Sometimes the socket the bulb gets plugged into can go bad. Usually this is caused by corrosion, which is caused my moisture entering the socket. However, it can also end up failing due to poor connection of the wires in the back.

If the bulb and fuse both check out good, check the condition of the socket while you have the bulb out of it. Look for any discoloration, like white, blue or brown, and bent or broken pins.

It is also a good idea at this point to check electrical current with a multimeter at the socket. No electricity reaching the pins means a failure somewhere up the electrical line.

See Also: 5 Reasons Your Reverse Lights Don’t Work

#4 – Worn Out Wiring

damaged wiring

If there is no electrical current reaching the socket, and fuses have checked out good, it is very probable there is a damaged or broken wire somewhere along the line.

At this point, you’ll need to obtain a wiring diagram and visually inspect the wires along the tail light circuit for broken wires or cracked insulation.

Be sure to check the body grounds coming off this circuit as well. A dirty, loose, or broken ground wire will cause a failure in delivery of electricity to the sockets as well.

Read Also: 5 Symptoms of a Faulty BCM

#5 – Control Switch Failure

lighting-control-switch

Another cause for tail lights not turning on is the switch that controls them. The head light switch on the dash can fail as well, and should be checked of everything else has checked out good.

Normally, this switch turns on head lights, tail lights, and parking lights. If all other parts of the tail light circuit are in proper working order, it’s possible this switch has failed. This can be pulled out from the dash and checked with a multimeter to verify it has failed.

Related: 4 Signs of a Faulty Brake Light Switch

#6 – Dirty or Bad Ambient Light Sensor

ambient light sensor

Many modern cars also have an ambient light sensor on the dash. This allows the vehicle’s computer to automatically turn the head lights and tail lights on and off according to how light or dark it is outside.

Some also turn off daytime running lights on newer vehicles. If both your parking lights and headlights don’t turn on but your brake lights still do, this is the likely culprit.

If this sensor goes bad, or gets too dirty, it cannot tell if it is light or dark outside, and may not turn on the lights. But again, this would affect both the head lights and tail lights, and could be easily tested by manually turning the head light switch to the on position.

See Also: Headlight Comparison (HID vs LED vs Laser)

#7 – Faulty Light Control Module or Body Control Module

bad body control module symptoms

Modern vehicles use electronic modules to control various systems, including lights. The Body Control Module (BCM) or Light Control Module (LCM) on certain cars can sometimes malfunction, causing issues with the tail lights while leaving the brake lights functional.

These modules receive input from switches and sensors, then send signals to activate the appropriate lights. If the module responsible for tail lights malfunctions, it may not send the correct signal to turn them on, even when other lights work normally.

Diagnosing a faulty control module often requires specialized diagnostic equipment. If you’ve checked all other components and can’t find the issue, the problem might lie within one of these modules. But it’s important to discount all other possible causes as control module failure is fairly rare (and not cheap).

#8 – Corroded or Loose Battery Terminals

car battery corrosion

While it might seem unrelated, corroded or loose battery terminals can cause various electrical issues, including problems with tail lights. The battery provides power to all electrical systems in your vehicle, and poor connections can lead to inconsistent power delivery.

Corrosion on battery terminals looks like a white, blue, or greenish powdery substance. This buildup can prevent proper electrical flow. Similarly, if the terminals are loose, they may not maintain consistent contact, leading to intermittent electrical problems.

Check your battery terminals for any signs of corrosion or looseness. If you find corrosion, clean the terminals (follow our directions). Make sure the connections are tight, but be careful not to overtighten them.

How to Test Your Tail Lights

test brake lights in garage

The simplest way to check your tail light and brake light operation is to ask someone else for help. Have a friend, family member, or neighbor either press the brake pedal while you observe the lights, or watch the lights for you while you operate the pedal.

But what if nobody else is around? Here’s how to test tail lights by yourself:

Garage Door or Wall Method:

    • Park with the rear of your vehicle backed up close to a garage door (inside or outside), wall, or fence.
    • Turn on your headlights.
    • Exit the vehicle and check for the red glow of tail lights on the wall.
    • Return to the driver’s seat, press the brake pedal, and look for a brighter red reflection.

Reflective Surface Method:

    • Find a large window or reflective surface in a parking lot.
    • Back up close to it, leaving enough room to exit your vehicle.
    • Turn on your headlights and check the reflection for your tail lights.
    • Apply the brake pedal and look for the brake lights in the reflection.

Camera Method:

    • Set up your smartphone to record video of the rear of your car.
    • Start recording, then get in your car.
    • Turn on your headlights, press the brake pedal, and activate turn signals.
    • Saying out loud when you are pressing the brake pedal also helps.
    • Review the video to check all light functions.
  •  
Mark Stevens

68 Comments

  1. My driver side side lights turn on OK until I start the engine. Within 10 seconds, they go off. Any ideas?

    1. What is the year, make, and model? Do you only notice the issue on one side of the vehicle? Do the lights take the same amount of time to turn off each time you start the vehicle?

  2. Installed LED headlights on my 2012 Honda Fit and also LED rear turn signal bulbs. Now day time rear tail lights don’t turn on. Brake lights turn on if I step on the pedal but I noticed the top hatch brake light turn on differently that before? Any advice would be appreciated

    1. LED lights often need a resistor if you are replacing halogen bulbs. This is because they require much less power than a halogen bulb would.

  3. I have a 2009 Subaru wrx and my tail and license plate light doesn’t work,I have replaced the tail light bulbs already and nothing.Also noticed when checking the fuse that controls the tail lights under the dash doesn’t have any circuit,what could be the problem??? TIA

  4. i dissconected all lights up front and in the back and soon as i turn on my lights my tail fuse instantly blows even after switching all bulbs. my dash lights dont work either in my 2004 toyota corolla ce. i dissconnected my drl relay and the fuse didnt blow

    1. Sounds like you have a short somewhere. The short could be anywhere on the part of the circuit that is shared with the tail fuse, but I would start by looking near the fuse box and looking near each of the light connectors (particularly the DRLs). If you have a multimeter and know how to use it, that may help a lot for troubleshooting.

  5. My tail lights from my challenger sxt 2014 v6 won’t turn on when I switch the lights on the brake lights work

    1. Check to see if that vehicle uses different bulbs for the tail lights and the brake lights. Perhaps the tail light bulbs burned out.

  6. I have a 2009 GMC Sierra, I’m currently having issues with the lights not turning on on the left side of the truck. My bulb for the license plate, tail light and LED strip on the headlight all on the left side do not want to turn on, the brake lights, sing all lights, and actual head light work. I’ve took the bulbs out and swapped them and they still wouldn’t work. Any suggestions?

    1. I would take a look at the wiring diagram for the lighting and see what circuit those lights share, then start looking at that section of wiring harness. Check fuses as well.

      Forums may have this information and they might even be able to tell you a likely cause if this is a common problem.

  7. I have an MG TF replica car built 34 years ago from a 1965 Triumph Herald chassis and 1968 Ford Escort, so I don’t have a wiring diagram. My headlights come on but not my tail lights at the same time when I turn on the spdt light switch. This switch also operates the parking lights which are okay. The rear light assemblies each consist of 3 festoon bulbs that are illuminating. The brake lights work as do the left and right indicators.

    1. Hmm, that’s tricky. Pull the tail lights and see if you have continuity using a multimeter. If you have continuity, you probably have bad bulbs. If you don’t have continuity, there’s probably a wiring issue somewhere in the harness that’s preventing the signal from reaching your tail lights.

  8. Tail lights come on when not on auto, but do not come on when lights are on auto. 2007 highlander

  9. my tail light doesn’t work and i can not find the fuse to check it, the diagram on the fuse box doesn’t show tail lights. i own a Colorado 2015

    1. Have you tried replacing the bulb(s)? If it’s not a bulb check the body control module fuses. I believe the tail lights will be part of a BCM circuit, but I would expect a few other accessories to stop working if a BCM fuse were out.

    1. The bulbs haven’t burnt out, have they? You may need to probe around with a multimeter to figure out why those lights aren’t getting any power. Make sure power is reaching the harness where the bulbs plug into.

  10. I have a 2008 Dodge 1500 ram. My problem is. Everything works properly except my right side front and back tail lights put test light on rear tail lights no power.

    1. Have you checked your fuses? Make sure you don’t have a blown fuse before you go too deep into troubleshooting the wiring.

  11. My 2016 Mitsubishi outlander sports rear light on passenger side was going off and
    On for a few weeks and now it doesn’t work,do I have to buy the led light kit or could it still be the fuse

    1. It could be the bulb, a bad ground, or possibly water in the taillight that corroded the connection to the bulb. I doubt it’s the fuse but it wouldn’t hurt to check it.

      1. When making a left turn my signal on all of a sudden it starts flashing to the right like I’m turning right and I haven’t turned left yet what do y on u think???

  12. I have a grand marquis 2002
    The rigth back tail ligth was cracked and tape. I replaced it and when i did i damage i wire and found it and fixed it
    But now turn signals , brake ligth only work when i turn headlights on and cruise control dont work and a/c is not gettin power. Plz plz plz help

    1. Sounds like an electrical short or a bad ground. Check your grounds in the area near the tail light and make sure the wire was repaired properly.

  13. On my 1999 Buick Lasbre the left brake light and turn signal does not work. The right side works. The bulbs are good, and fuse is good. The left indicator light comes on and stays on when I turn it on but does not flash.

    Where do I go from here?

    1. Even though the bulbs illuminate, I’d try replacing them if you haven’t already. Next, I’d look at the turn signal relay.

  14. My 2012 Kia Sorento tail light (left side) front driver side parking light goes out frequently, when I cut the lights off then on they turn back on, I tried taking it to the dealer and another shop, they cannot figure out what’s going on.

  15. 04 ford territory I’ve l9st all of my park lightsfog lights and dash lights checked all fuses replaced the brake lights aswell with the correct ones still nothing can anyone help?

    1. Now i have a crack n my tail light cover, i had water n it had 2 take off and let it out, changed the bulb because the tail light doesn’t come on but the brake light do and the turn signal do…do you think the mini bulb is the problem?..

  16. Installed LED bulbs in a 2019 Toyota Tacoma .All lights worked normally. Installed a curt t connector for a led tailgate bar and now I have no rear running lights. Blinkers,backup, hazard and brake lights working but no running lights when you switch on headlights. Scratching my head. Help me!

  17. I have an 2002 Acura Rl 3.5 my running lights don’t work at night but the brake lights an all work but when my foot is not on the brake my lights are not on when they should be at night can anyone help I’ve had my wiring looked at my light bulbs changed an my fuses all looked over but the problem still stands

    1. I am having the exact same problem with my 98 Honda Civic. Did you ever find an answer or figure out the problem? (I hope so😀)

  18. My 2012 Chevrolet Captiva Sport LTZ 3.0 L 6 Cylinder is having issues with its daytime running lights/Tail Lights arent working at all. I bought a brand new LED bulbs for it have checked all the fuses that are possibly be the right ones and yet I still have no tail lights but I have perfect brake lights

  19. i have a 2013 hyundai elantra. When my headlights are on none of my brake lights work but when headlights are off, one brake light works. i changed fuses and brake stop switch. i noticed today the sockets to my brake wire harness are burned…could this be causing the issues?

    1. That could very well be it. You may have corrosion in there or it not being properly grounded. Sorry, hard to say without seeing.

  20. So my 2016 ford super duty’s tail lights just went out, my hazards, signals and brake light still work. What should I do

  21. I have a problem my tail light and dash light fuse kept blowing checked all my wires all the way to the tail lights them self bulbs are good the orange wire from my light swich to the fuse box kept getting hot so replaced that wire worked for a couple days then started again so decided to bypass the fuse box and put inline fuse from battery to red main wire from fuse circuit i bypassed. but light still wont turn on is there more then one wire in my switch that has to to connect with the main red wire other then the orange wire i replaced completely stumped

  22. Hi my Fiat Ducato Motorhome is having an issue-1 tail light and front light come on when the brake pedal is pressed but brake lights do not. The tail light comes on and stays on when the I press the keyfob to open the doors etc.

    1. You have some type of voltage bleed or short from one circuit to another. But I’d first check that the correct bulbs were being used. I’ve heard cases where a single-pole bulb was used in place of a double-pole bulb which caused a short.

  23. One of the Tail back light is not working. The very strange thing is when I swap the bulbs around the lights works interchangeably, Even when I change the bulbs with brand new bulbs is the same thing.

    please help

    1. Sounds like an issue with the socket or wiring. Check for corrosion in the socket first and any damaged wiring.

      1. Hey! So my 2015 Nissan Juke sl tail light went out. I brought it to Nissan and they said the connector has corrosion. He told me it would cost close to 500 to fix. What can I do to fix this or is there somewhere this can be fixed for less?

        1. I don’t know if it can be fixed for less, you’ll have to call shops in your area to see what their estimates are.

          Do a bit of reading on the Juke forums and YouTube and you may find a video where someone has replaced this exact part. After watching the video, determine if this is something you would be comfortable doing yourself. If so, you can probably save a lot of money by doing it yourself.

    2. 2013 dodge dart. My rear tail lights turn on briefly and shut right off I cant get them to stay on for a length of time. But my turn signals brake lights all that are still working. My headlights stay on in auto mode and manual. If I switch the dial back to off then back on the tail lights flash on then off again

  24. Gmc sonoma has all lights originally but after a bit when using breaks the tail light on driver side goes dim. In reverse it goes out completely. After cleaning out the grounds in all locations and rewiring any connections and cleaning any debris and rust away to check for any issues, now its different. Now when applying breaks they light up fine but in park, we are losing that same tail light completely. its bright now but in park its out. Already gotten a fix it ticket and teo earnings now. Camt figure out this issue. Cant find shorts either. Think maybe the wiring up front somewhere, someone mentioned replacing the turn signal on that side as it is also flashing crazy. Maybe a fuse but the fuses are all fine that we seen. Could also be somewhere in the panel.

    Just a bit background, my bf got the truck from his dad who did all kinds of work on it and even had shorted wiring in the door which caused a lot of problems electrically until the wires were unpinched and wrapped back up. Unsure if related but originally the door being shut wrong (door is drooping and has been repaired once already. Needs welding.) the trucj would stall until we wriggled them around. Battery was constantly draining and eventually died completeLy. This whole taillight issue began around two different circumstances and we dont know if it is related. One was we noticed it occured after using a trailor which made the lights flicker when hooked up. It also makes a different trucks light go dim like ours used to. the second is we changed the battery from a used parts yard that same time frame. Likely not the root of the issue tho. Just something im taking into account.

  25. The drivers side tail light on my 2007 Jeep Liberty is not working I have replaced the bulb and socket and still does not work what else should I look for

    1. Check the fuse, look for any correction on the connector to the socket, and look for any damage to the wiring.

      1. 2015 Yukon has break light has blinkers has back up bulbs. I thought it was a break in led board but it wasn’t. The issue is no tail lights at all but aren’t the tail light and break light on the same strip of LEDs?

        1. I don’t know, but the factory service manual should have a wiring diagram that will tell you. Might check a Haynes or Chilton manual as well.

        2. I was thinking that stop and turn was on the same and tail was on it’s own circuit but, I could be wrong.

  26. my 81 toyo corolla liftback tail lights are all cracked and tapped and the socket are all falling apart, i am going to take the tail lights out and fill the holes and put a 48 inch quad row LED light bar in it’s place can i use the original tail light’s wiring?? the LED bar is split and has right and left 4 wire connectors on each side?

    1. It’s hard to say but usually the manufacturer of the light bar will have it correctly wired for a swap.

    2. Most cars don’t allow for LED lights the flasher element is made for a bigger pull on the electrical connector and if you want to go led you would have to replace the flasher element.

    1. First confirm the bulbs are the correct type/size. If the contacts don’t line up and fit securely, they won’t light up. Otherwise, see numbers 1, 3, and 4 above.

      1. My Park lights don’t work on my Dodge truck and come to find out my computer in this truck is bad so it’s like a $600 part so you might check your ECU.

        1. I would have thought that it was the bcm not ecu because the bcm controls light functions where as the ecu controls engine functions

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