1993 GMC Sonoma Owner's Manual - Page 131

Comfort Controls Flow-Through Venfilation System KO502 Your vehicle's flow-through ventilation system supplies outside air to the inside of your vehicle when it ismoving.Withthesidewindowsclosed,air will flow into the front air inlet grilles, through the vehicle, and out the rear air exhaust valves. Outside air will also enter the ve,hicle when the heater or the air conditioning fan isrunning. Ventilation Tips Keepthe hood andfrontairinletfree ofice,snow,oranyother obstruction (such as leaves).Theheateranddefroster will workfar better, reducing the chance of fogging the inside ofyourwindows. Whenyouenter a vehicle in cold weather,turn the blowerfan to HI for a fewmoments before driving off. This helps clear the intake ducts of snow and moisture, and reduces the chance of fogging the inside of your windows. Keep the air path underthefrontseatsclear to circulate throughout your vehicle. ofobjects.Thishelpsair 3-3