Air Distribution System

Air Distribution (Upper):

Air Distribution (Bi-Level):

Air Distribution (Lower):

Air Distribution (Defrost):

Air Distribution (Defog):

Control of air through the system is regulated by vacuum. At various positions on the control, mode valves mix and direct cooled, heated and outside air through the air ducts. The flow of air from the HVAC system during the various modes of operation is as follows:

^ Off-All outlets, light bleed.
^ Max-Instrument panel outlets recirculation air.
^ Norm, A/C-Instrument panel outlets outside air
^ Bi/Level-Instrument panel outlets and floor outlets outside air.
^ Vent-Instrument panel outlets, outside air, no compressor operation.
^ Heater-Floor outlets and a small amount from defroster duct.
^ Defog-Equal amounts floor and defrost.
^ Defrost-Defroster outlets and a small amount from the floor outlets. The operation of the cooling fan is controlled by the PCM through the cooling fan relay. Complete wiring diagrams and diagnosis for the A/C electrical system are in additional diagnostic information regarding airflow and vacuum logic.

Vacuum Lines

Vacuum lines are molded to a connector which is attached to the control knob. In case of leakage or hose collapse, it will not be necessary to replace the entire harness. Replacement can be made by cutting the hose and inserting a plastic connector.

Vacuum Tank

Vacuum Tank:

During heavy acceleration, the vacuum supply drops. A check valve in the vacuum tank maintains vacuum so that, under load conditions, vacuum will be available for continuous use.

Ducts and Outlets

A system of ducts and outlets direct air to the passenger compartment. In cases of poor air output, defroster, heater, A/C and vent ducts should be checked for obstructions, such as leaves, dirt, objects, etc. A/C systems also come equipped with side window defoggers. Removal and installation of all ductwork is covered under On-Vehicle Service.