Hello to all the Mercedes owners! I once have already tried to do something with that button because the light was flashing and after some time went out completely. Last time I fixed only one contact with a soldering iron, although I should have fixed all of them because the board bends a little bit when pressing the button itself. It worked fine for four approximately four months and started flashing again. So I took my camera and went to fix it once again, this time more thoroughly. By the way, in the Mercedes auto repair shop where I just bought the car the electrical technician who specialized on the diagnosis and who “works with Mercedes for ten years and knows them by heart” has told me that the only solution is to replace the button completely.
So, let us disassemble the central extension housing in order to get to the panel with the buttons. I am not going to describe the process in all the details because this operation is really simple, however here is the video on the whole process (same for the restyled version as well).
After disassembling we see the following picture: the button attaching plug is located under the cover, which has locks. Unlock it and detach the connector. Now the plastic button block is located inside of the aluminum panel with locks – there are eight of them if I am not mistaken, so unlock them and take out the buttons.
Now, the hazard lights button together with two other ones are simply inserted into the contacts from one side – remove them. In order to get to the board unscrew the five or six small screws and separate the device.
What we do next is we press the hazard lights button and take it out. Take it easy – there are two small springs that will remain on the board, so be sure not to lose them. Now that we have got the button in our hands, pry up the two lockers and remove the red cover. Now we can see a small board that does not contact.
Use the multi-meter to test the two small resistors and the light emitting diode (it will flash from the multi-meter only in one direction). All the elements are ok but they do not receive the signal from the main contacts.
Now we need to go with a soldering iron through all the board tracks, marked with black color. You can use really thin wires to connect them or simply solder as usual. I managed to use a wire to connect to the resistor and solder as usual between the resistor and the light emitting diode because there is a real space shortage. After that we need to check the resistance with a multi-meter, and to be completely sure a nine-volt battery may be used as well. Everything works well!
Now let us assemble everything back and I hope we will not return to this topic anymore. Thank you for your attention!
Provided by anikey124