1993 Chevrolet Lumina Owner's Manual - Page 104
1993 Chevrolet Lumina Manual
Page 104 highlights
Comfort Controls Audio Systems & cw3012 Rear Window Defogger(CONT.) Don't usea razor blade 0. something elsesharp on the insid of the rear window.If you do, you could cutor damage the warming grid, and the repairs wouldn't be covered by your warranty. Flow-Through Ventilation System Your Chevrolet's flow-through ventilation system supplies outside air into thevehicle when it is moving. Outside air will also enter the vehicle when the heater or theair conditioning fan is running. I Ventilation Tips Keep the hood and front air inlet free of ice, snow,or any other obstruction (such as leaves). The heater and defroster will work far better, reducing the chance of fogging the inside of your windows. When you enter a vehicle in cold weather, set the blower fan to the highest setting for a few moments before driving off. This helps clearthe intake ducts of snow and moisture, and reducesthe chance of fogging the inside of your windows. Keep the air path under the front seats clear of objects. This helps air to circulate throughout your vehicle. I.. I02