1997 Pontiac Trans Sport Owner's Manual - Page 219

Rear Air Vents: To maximize airflow through rear the heater outlet, place the left bucket seatin thesecond row in the forward position (see "Adjusting Rear Seats" in the Index). Defogging and Defrosting To rapidly defrostthe windshield, turnthe temperature control knob all the way clockwise (to the red area) and turn the mode knob to DEFROST. Adjust the fan to the highest speed. To keep the windshield clearand bring in heated a r i through t e heater ducts,turn the mode knob toDEFOG. h When the temperature outside is above Ereezing, the air conditioner compressor will run in these settings to help remove moisturefrom theair. Your vehicle is equipped withside window defogger vents located on the top of the instrument panel. For additional side window defogging, turn the mode knob to the BI-LEVEL setting and adjust the fan to the highest speed. Aim the side vents on the instrument panel towardthe side windows. For increased airflow to the sid'e vents, close the center vents. The vent behindthe left rear seat is the cold air return vent. Be sure to keep it free of obstructions. Please keepthe area around the base of the center instrument panelconsole and between and under the front seats free of objects that could obstruct airflow to the rear. 3-8