Moin, I have a articulated bus with retarder. Can anyone tell me how this is operated? I once have a foot switch for the motor brake. Unfortunately, this is without function. Then I have a button in the dashboard for the motor adjustment. It works. I had the idea to connect the foot switch to the button first, but had to find that the button against plus and the foot switch switches against mass. Is the foot switch usually for the operation of the retarder u and the engine brake thought and the button only to turn off the engine? Who knows these things and can help me? Thanks and greeting Michl