The heater system provides the following functions:
The blower fan draws outside air into the heater module from the plenum
at the base of the windshield. Additional outside air, called ram air, is
forced into the heater module by the forward movement of the vehicle. The
heater module heats the air as required. Ducts then carry the air to the proper
outlets for discharge into the passenger compartment. The operator controls
the blower motor speed, the mode of operation, and the temperature of the
incoming air through an HVAC control assembly in the instrument panel.
The heater module contains components that heat the air flowing through
the heater module and direct the air to the proper ducts and outlets. These
components are enclosed inside a two-part housing. The front housing mounts
to the front of the cowl panel in the engine compartment. The rear housing
mounts to the rear of the cowl panel in the passenger compartment under the
instrument panel.