The brake lights are very important when driving your Mini Cooper. Faulty brake lights can cause a vehicle to hit you from behind or can lead to a "fix it" ticket from the local authorities. Troubleshooting the brake lights on a Mini Cooper is a simple process that only requires a few tools. The Mini Cooper brake lights use 21/5 watt bulbs which can be purchased at most automotive parts suppliers.
Turn off the Mini Cooper's engine and open the bonnet.
Disconnect the battery. Use the wrench to remove the negative terminal first, then remove the positive terminal.
Open the rear door and remove the cover of the side trim panel in the cargo area. This will allow access to the tail lamp assembly.
Lightly pull on the electrical cord. If it is loose, securely plug it into the tail lamp assembly. If the problem still persists, there may be an issue with the bulb. Reconnect the battery.
Unplug the power supply by pulling the electrical connector out from the rear of the tail lamp assembly.
Release the bulb holder by pushing down on the tab. Apply pressure to the bulb while turning to the left to remove it.
Use a paper towel to place the replacement bulb into the tail lamp assembly until it clicks into place.
Reattach the power supply to the tail lamp assembly.
Reattach the cover of the side trim panel and close the rear door. If the problem persists, a fuse may have popped.
Open the driver's side door. On the left side of the footwell in the side trim panel in the interior fuse box. Press the fastener on the cover to open the box.
Locate the brake light fuses. They are labelled "Right Stop Lamp" and "Left Stop Lamp." If the metal inside the fuse is not in one piece, it will need to be replaced.
Use the accompanying tweezers located in the fuse box to remove the broken fuse. Replace the fuse with one of the same amperage.
Close the fuse box. Close the driver's side door.
Reconnect the battery to the vehicle. Connect the negative terminal first, then the positive terminal. Close the bonnet.