D Group 37 Wiring diagram Component wiring diagram FH12, FH16 LHD Horn Reverse warner Windscreen wipers and washers, headlamp wipers and washers Air conditioning Cab heater (DL1C) Engine/cab heater (DW80) Heated seat Electrically adjustable seat Electrically heated rearview mirror Electrically operated rearview mirror Air dryer Fuel filter heater Cab tilt unit Radio, voltage converter, loudspeaker, alarm clock/timer Electrically operated window winder Seat belt Electrically operated door lock 3