Brake lights on trunk not working

The brake lights on my trunk aren't working. This is after replacing all the bulbs and fuses (even though the tester said they were fine.) the brake light in the rear window works, and the tail lights work. Blinkers, reverse lights, headlights, high beams – everything works except the trunk brake lights. The only other thing not working is my cruise control. Might that be related? If not, what would cause the brake lights to stop working just on my trunk?
Experienced mechanics share their insights in answering this question :
For some reason, when consulting the wiring diagram, I don’t see a trunk mounted brake light listed. I only see the high mount (one in the rear window) listed. Regardless, if the trunk bulb is not working with a new bulb, there is a problem with the circuit. Check for both power and ground at the bulb. Once you’ve determined which is lacking, you’ll have to trace the circuit to determine where the problem lies. Since you said all of the other brake lights work, the cruise control is likely unrelated. Electrical diagnosis can be difficult, so I suggest you have a trained professional tackle the problem with your brake lights for you.

How to Identify and Fix Common car Problems ?

Our sources include academic articles, blog posts, and personal essays from experienced mechanics :

If one or more of your brake lights aren`t working properly, it could mean one of three things: The brake light system fuse is blown, the brake light bulbs are burned out or the brake light wiring switch is broken. All these issues are easy to troubleshoot.
When the lower lights do not come on and only the third-brake light works, the brake-light switch may be ruled out. Again try the emergency-flashers to check for wiring, socket and lamp problems. If the flashers work, check for blown fuses as a few vehicles use separate circuits for the lower and third brake lights.
In 1986, the Center High Mount Stop Lamp (CHMSL) – or what we all think of as the “third brake light” – was mandated for use in the United States. The theory, of course, was that a brake light placed higher and more prominently at the back of the car would help to prevent rear-end collisions.
The Light Control Module (LCM) is an important component of a vehicle because it controls all of the car`s lights, as well as the horn function.
It is a 15amp fuse that powers the stop light switch on the brake pedal. The brake light switch sends power to rear brake lights.
That means a car company can`t stick its headlights on a car`s hood, and it can`t stick its brake lights on a car`s trunk, because those items could be open while you`re driving, potentially rendering it impossible to see your headlights or brake lights.
Colloquially referred to as brake lights, they are installed in pairs at the rear corners of the vehicle. In North America, since 1986, all vehicles feature a third brake light.
Rear position lights (tail lights)

Conspicuity for the rear of a vehicle is provided by rear position lights (also called tail lights).

The trunk light bulb is a small light bulb that is located on the top part of a car`s trunk. Its primary function is to light up the trunk when the lid is opened. Since it is seldom used, the trunk light bulb can last for years.
You only need a Brake-Lite Relay if you`re installing a supplemental towed vehicle braking system that pushes or pulls the brake pedal. With the engine off, step on your brakes. If the brake lights do not illuminate, you do not need a Brake-lite Relay.
Blown Fuse or Broken Fuse Box

If your brake light switch works perfectly fine and yet the brake light doesn`t illuminate, you should check for a blown fuse or a broken fuse box. This is important because both these components affect the brake light circuit.

Electrical Issues

If you have a malfunctioning tail light, it could be a matter of a blown fuse. The fuses work with your car`s electrical panel and if they`re blown, it can cause several lights to stop working. Replace the fuse and see if this helps. Another issue may be related to your wiring.

Relevant Questions and Answers :

the most relevant questions and answers related to your specific issue

EPC light on 2004 Jetta. Code said brake switch faulty, but brakes lights worked. Replaced brake switch, now no brake lights.
ANSWER : Hi there. The first thing that pops in my mind beyond of what you have listed is perhaps the electrical harness attached to the brake switch. Perhaps the harness itself is damaged or you have an exposed wire, loose ground wire somewhere. You might want to have a professional mobile mechanic come to your location and complete a brake lights not working inspection to help you diagnose this issue.

Brake lights on trunk not working
ANSWER : For some reason, when consulting the wiring diagram, I don’t see a trunk mounted brake light listed. I only see the high mount (one in the rear window) listed. Regardless, if the trunk bulb is not working with a new bulb, there is a problem with the circuit. Check for both power and ground at the bulb. Once you’ve determined which is lacking, you’ll have to trace the circuit to determine where the problem lies. Since you said all of the other brake lights work, the cruise control is likely unrelated. Electrical diagnosis can be difficult, so I suggest you have a trained professional tackle the problem with your brake lights for you.

Okay so when I turn my lights on at night my brake lights do not work, when I don’t have my lights on they work fine.
ANSWER : Hi there. Based on your inquiry, it’s highly probable that you have a damaged light switch or some electrical fault inside the turn signal relay. However, it’s also possible that the brake switch above the brake pedal could also be the source of your problem. Due to the fact that multiple electrical components might be causing this issue, it’s a smart idea to first have a professional mobile mechanic complete a brake lights are not working inspection, so they can determine what’s causing all of these issues and recommend the right repairs.

Brake lights are not working. replaced brake light swtch still no brake lights. the third brake light the connection was melted at
ANSWER : The first thing to do is to repair third brake light and replace the brake light fuse and then see if the third brake lights work and the lower lights start working? If only the 3rd brake light starts working then you may need a further checks on the turn signal flasher or switch could be bad.

All dashboard lights and tail lights do not work after driving through a lot of snow. Headlights work. And brake lights work.
ANSWER : Hello. We’ll be happy to help you. There are a few things that I recommend checking to discover why your lighting system is malfunctioning. The headlight dimmer switch should be checked. Along with the wiring harness above the right front tire behind the fender well cover. Also
the main fuse under the hood should be inspected because other people with your particular vehicle have had similar lighting issues if that fuse goes bad. It will be a great idea to check the rest of the fuses in that area too while checking the main fuse. Once the fuses are checked inside of the main fuse box then I would check the fuses inside of their interior fuse box. The interior fuse box should be located on the driver side of the dashboard near where your legs would be. If you need more assistance with repairing your vehicle please keep in mind that our organization provides Mobile Mechanics who can help you diagnose and repair your vehicle, all at competitive rates.

Dash, Tail/brake, dome, trunk, glovebox, and door lights won’t work, dash doing weird things.
ANSWER : Hi there. Sure would appear a lot is going on electrically all at once. This could be, a problem in the PDC (power distribution center). The PDC is typically located under the hood and contains numerous fuses and relays. I don’t believe any one fuse will resolve all of the electrical issues. There is a possibility, it is not a power supply issue. It may be, the result of a poor electrical ground common to the inoperative components. Proper circuit testing should be performed. This would confirm the cause of multiple electrical failures. I recommend having your vehicle’s electrical problems be diagnosed and repaired by a certified technician, such as one from YourMechanic.

When I put my foot on the brake my back left brake light goes off, when I take it off the brake the brake light comes on
ANSWER : I would suggest trying to disconnect and reconnect the wiring to the rear lights. I have seen these older Toyota vehicles rear lighting short out on the lights themselves due to the way the light circuit was made on the lamp housing. Look at the housing circuit on the light to see if one is touching another, and that could tell you why it is malfunctioning. There could also be a problem with the brake light switch. If you are not comfortable dealing with wires, I recommend getting in touch with a certified mechanic who can look at your brake light issue for you to see what’s going on.

No dash lights, back right tail light is out, no parking lights. Brake lights work though as does head lights.
ANSWER : Hi there. In many cases, when you have electrical problems like you’re describing, it’s caused by multiple electrical component failure. It’s likely that a few electrical relays are not working; especially if you have systems that utilize the same components (such as your brake light and tail lights). I would recommend having a professional mobile mechanic come to your location to complete an electrical problems inspection first, so they can pinpoint what is damaged and recommend the right repairs.