Roadster Brake Light Switch
How to find and replace the brake light switch in a Roadster
Thanks to Jasmin for the pictures.
Finding and removing the brake light switch in the Roadster is much easier than on the fortwo.
No need for jacks, removing panels or access covers as it is reachable from inside the car.
The Fortwo brake switch usually suffered from water damage that ran down the wires
into the box that housed the switch. On the Roadster it is in a different place but still
prone to water damage due to the leaks that plague the Roadster.
To find the switch, look at the brake pedal and follow it up under the dash.
At the top you will see the brake light switch.
A simple quarter turn will release the switch from its holding bracket.
Pressing the brake pedal down at the same time can help removal of the switch.
Sounds simple but access is tight so I suggest opening the roof, sit on the driver's seat
the wrong way with your legs out the roof and put the top of your head on the brake pedal
to push it. That way you can see the switch and have both hands free.
Pull the electrical connection from the old switch and either test it or fit a new one.
The part number for a new Roadster brake light switch is A4525450009 but it is worth noting
that this is exactly the same as the switch in the fortwo except for the colour and the rubber bellows. So if you want you can use part numbers SQ0002128V02400000 or SA452540009 instead.