Temperature Control Knob

When temperature control knob is rotated toward cool air position, upper side of heater core is blocked by blend-air door. As a result, all air from blower motor by-passes heater core and flows into passenger compartment as cool air.

When temperature control knob is rotated toward warm air position, blend-air door will block cool air path. Cool air from blower motor now passes through heater core for maximum heating.

With temperature knob in middle position, blend-air will split air stream into 2 branches, one passing through heater core and on by-passing heater core. Various combinations of warm and cool air are available to meet various temperature requirements.