Brake Mod



While exploring online, I discovered a forum post describing a modification frequently applied to the US version of the Mazda 6, produced between 2000-2007, which enables the taillights to activate with the brake lights. Typically, these taillights only function with the parking lights. I then recognized that, since my vehicle is the European version, the modification process might require additional effort.

The European model of the Mazda 6 lacks lights bulbs in the tailgate; it only includes reverse lights. Therefore, I thought it would be interesting to add both the tail and brake lights combo to it.


For this mod you will be using a couple of things.

  • 10mm Socket.
  • Soldering Iron and Solder
  • Cable Cutter/Stripper/Peeler.
  • Heat shrink tubing.
  • Wire in different colors and lengths.
  • Dremel tool (for sanding, as cutting is messy)
  • Files
  • Drill
  • 3/4 Spade bit.
  • Small flat screwdriver.
  • Multimeter.

Required Parts

To simplify the process and acquire the items I needed, I ordered a trunk wire harness from the same year as my car. I assume that any harness from the same generation might work, but I wanted to be certain. Additionally, during a previous visit to the States, I managed to salvage an old 2003 Mazda 6 from a junkyard. I obtained the required bulbs and bulb sockets for this modification from that vehicle.

  • Mazda 6 Trunk wire harness.
  • Bulbs with their sockets. These need to be dual filament bulbs, and sockets with 3 pins.


We start by getting two of the connectors on our new/used extra wire harness. Specifically, the brake light connector and the reverse light connector.

Grasp the reverse light connector and flip it over to observe the small notch. This notch needs to be opened to disconnect one of the wires from the connector, specifically the red/yellow wire. Employ a small flathead screwdriver to pry it open.

When the notch is in its opened position, you will see two tabs inside, you have to apply force to bend them towards the center to be able to release the cable connector. Light force is required.

When you have your connectors free. Take the one you want to use, and insert it into the brake light connector. It turns out they are an exact match!

Repeat the same process for the other brake light/reverse light connectors, remember we need two of them

Remove the trunk trim

After that, remove the inboard combination lights, using following procedure.

You will notice (not much in the picture) that there is a faded cutout of the socket hole. This will serve us as guide to cut the hole for the bulb sockets.

After an arduous hour of cutting, filing, and sanding, you will have created a socket hole. I didn’t take pictures of the process, so I will describe my findings instead:

  • Avoid using a Dremel for this task; it will produce numerous small plastic shavings that are difficult to clean up.
  • Utilizing a spade drill bit to create the initial hole results in less dust compared to using a Dremel, as I’ve learned from experience.
  • Use the Dremel tool with a sanding bit to sand it down until the socket fits inside easily and can be turned without effort.
  • Utilize a file to gently sand the receiving end of the small plastic guides on the bulb socket until they can slide in and out effortlessly.
  • Sand, sand, sand! (Remember, patience is a virtue.)

You will end up with something like this

Great, isn’t it? Now, put everything back together in your car. It’s time to use the soldering iron.

Extend the cables to the necessary length to connect both of the previously made connectors. This will require cutting them from the additional wire harness you have purchased.

Also in order to perform the Brake mod, you will have to run a wire from the left brake light to your tailgate, that means you have to run it through the rubbery loom protector, just use a thick wire to fish it out, or use a wire fisher. the spoiler 3rd brake light if you have that available, splicing the positive cable, I chose red as my break light cable. (you can follow the forum post)

Connect everything up and you will have something like this (including red cable for brake light I painfully fish out):

Splice the remaining green, and black cable into the license plate wires. Make sure to identify the positive and negative cable. In my case both of the cables were black, so I had to use a multimeter to figure out ground. Make sure you do this! if you connect it backwards nothing good will come out!

Use electrical tape and zip ties to secure everything into the right place.

Solder the red cable into your left rear brake light connector (the one in the body of the car, not in the trunk lid), in my case it’s connected to a Green/Yellow cable, this cable goes to +12v when brakes are applied. Which in turn will power the second filament in our tailgate bulbs.

Connect everything the way it was, assemble back your trunk trim, turn on the parking lights and get ready for some mad braking!

If you have any question or comment, feel free to post them below.


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