See also:

Before changing a fuse
  Park the vehicle and apply the parking brake.   Switch off all electrical consumers.   Remove the SmartKey from the ignition lock. The fuses are located in various fuse boxes: ...

Snow chains
For safety reasons, Mercedes-Benz recommends that you only use snow chains which have been specially approved for your vehicle by Mercedes-Benz, or are of a corresponding standard of quality. ...

Problems with the seat heating
The seat heating has switched off prematurely or cannot be switched on. The vehicle's electrical system voltage is too low because too many electrical consumers are switched on. Switch off e ...