A vacuum regulates the control of air through the system. Various positions on the control cause the mode valves to mix and direct cooled, heated and outside air through the air ducts.

Air flows through the HVAC system as described for each of the following modes:

OFF: A light bleed of air flows from all of the outlets.

MAX: Recirculated air flows through the instrument panel outlets.

NORM, A/C: Outside air flows through the instrument panel outlets.

BI-LEVEL: 

Outside air flows through the following outlets:

VENT: 

Outside air flows through the instrument panel outlets. The compressor does not operate.

HEATER: 

Most of the air flows through the floor outlets. A small amount of air flows through the defroster duct.

DEFOG: 

Equal amounts of air flow through the floor outlets and the defrost outlets.

DEFROST: 

Most of the air flows through the defroster outlets. A small amount of air flows through the floor outlets.

The operation of the cooling fan is controlled by the PCM through the cooling fan relay.

Ducts and Outlets

A system of ducts and outlets direct air to the passenger compartment.

Obstructions in the ducts and outlets may cause poor air output. Inspect the following air passages for obstruction, such as leaves or dirt:

A/C systems also come equipped with side window defoggers.