Mode Control Lever (Standard System)
When in "OFF" position, the system is off. When in "HEATER" position, most of the air is delivered through the floor (heater) outlet with some air flow to the windshield (defroster) outlets.
The lever may be adjusted between "HEATER" and "DEF" to vary air distribution between floor air outlet and windshield outlet. In the "DEF" position, heated air is delivered to the windshield outlets with a small amount to the floor outlets.