2010 Mercedes GL-Class Owner's Manual - Page 175

Overview of climate control system functions and air vents For best possible performance of the climate control: X 173 Side air vents i For draft-free ventilation, move the adjustable center and side air vents to the middle position. Center air vents Example illustration driver's side : Left side defroster air vent, fixed ; Left side air vent, adjustable = Thumbwheel for air volume control for adjustable left side air vent X Opening/closing: Turn thumbwheel = in the required direction. Rear center console air vents : Left center air vent, adjustable ; Right center air vent, adjustable = Thumbwheel for air volume control for adjustable right center air vent ? Thumbwheel for air volume control for adjustable left center air vent X Opening/closing: Turn thumbwheels = and ? in the required direction. : Left rear center air vent, adjustable ; Right rear center air vent, adjustable = Rear climate control panel When the front climate control panel is switched on or off, the air supply through the rear center air vents is also switched on or off. Z Controls in detail Keep the air intake grille in front of the windshield free of snow, leaves, sticks, and any other debris. X Always keep all air vents and grilles in the passenger compartment free from obstruction.