Defrost Mode
When the Defrost mode is selected, outside air enters the module and passes through the evaporator core. The air then passes through the heater core where it is heated. For maximum defrosting or in high humidity conditions do not engage the Recirc button. After the air passes through the heater core most of the air is directed through the mode valve to the defroster outlet. A small amount of bleed air will pass by the mode valve and out the lower air outlet. The figure shows air flow with the temperature knob set to full hot.
IMPORTANT:
^ Defrost/Defogging Windows: This setting directs the air through the windshield defroster outlets onto the windshield and past the front side windows. Use this setting if windows are fogged or icy. This setting will also help defog the front side window. Set the control knob to defrost and set the temperature to full hot (far to the right). To quickly clear the windows, put the fan control switch to high and push the A/C button. (An indicator light will go on.)
^ To keep the glass fog free, the mode select knob should be positioned between Heater and Defrost. The Recirc button should be left Off. The mode knob should be used to regulate air flow depending on driving conditions.