K 1500 Yukon 4WD V8-5.3L VIN T (2000)
The heater module contains components that heat the air, and direct the air to the proper ducts and outlets. The 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.
Modes Description
UPPER MODE
With the mode knob in the Upper position, the vent valve opens so air can flow to the instrument panel outlet ducts.
LOWER MODE
When the mode knob is in the Lower position, the vent valve partially closes. The defroster valve remains closed. The blower fan heats the air and
directs the heated air to the defroster valve. The defroster valve sends most of the airflow to the heater duct and some to the defroster nozzle.
BI-LEVEL MODE
When the mode knob moves to the Bi-Level position, the defroster valve moves to uncover more of the opening to the defroster. An increasing
amount of air flows to the defroster nozzle, and a decreasing amount of air flows to the heater duct.
DEFROST MODE
When the mode knob is in the Defrost position, the defroster valve moves to fully uncover the opening to the defroster nozzle and restrict the opening
to the heater duct. The defroster nozzle receives the maximum airflow, with only a little amount of airflow coming from the heater duct.
Odor Description
Some vehicles may experience odors emitted from the air conditioning system primarily at start up in hot, humid climates. This odor may be the result of
debris in the heater and evaporator module or microbial growth on the evaporator core.
A single application of the Goodwrench Air Conditioning System Deodorizer will remove odor from the air conditioning system.
