1993 Cadillac Seville Owner's Manual - Page 163

Electronic Climate Control Features A/C Purge If your vehicle is sitting out on a hotday and you have it set on AUTO, the air first flow out thefloor air ducts for few seconds. That is will a normal. This is to expel hot air in the air ducts. As the air is cooled, the flow will move through theA/C outlets. Cold Weather Purge On cold days when your system isfirst turned on, at any setting other than Defroster,DEFOG orOFF a small amount of air will flow through the defroster duct preventing windshield from fogging. your Automatic Defog When using your wipers or rearwindow defogger for several minutes, the system senses that a humid condition exists. When this happens, air flow will be directed to thewindshield and floor ducts keep your side glass to and windshield clear. Manually Recirculate Inside Air There may be times, when you don't want air from the outside. To recirculate the air from the inside only, just set the temperature to 60°F (16°C) and adjustyour fan speed. DEFOG Push this button todivide the air between the windshield and the heater ducts. This is useful when fog appears on the windshield or side glass due to a suddenrain. 149