1996 Ford Mustang Owner's Manual - Page 82

Under normal conditions, the SELECT knob should be left in any position other than MAX A/C or OFF when the vehicle is parked. This allows the vehicle to "breathe" through the outside air inlet duct. The Heater Only System You can heat the inside of your vehicle, defrost the windshield, or use the vents by adjusting the three knobs in the center of the instrument panel: u FAN u TEMP u SELECT The knobs that control the standard heating only system To heat the inside of your vehicle, turn the SELECT knob to FLOOR, turn the TEMP knob all the way to the end of the red range (full right) and turn the FAN knob to HI. After the vehicle is warm, the temperature and blower speed can be adjusted to maintain a comfortable temperature. To defrost the windshield and side windows, turn the SELECT knob to Defrost symbol, turn the TEMP knob to the end of the red range (full right) and turn the FAN knob to HI. 82