Symptoms - HVAC Systems - Manual. GMC Truck Sierra Denali 2009

For 1990-2009 cars only

Makes 🢒 GMC_Truck 🢒 2009 🢒 Sierra Denali 🢒 HVAC 🢒 HVAC - Manual 🢒 Symptoms - HVAC Systems - Manual

Important: Review the system operation in order to familiarize yourself with the system functions. Refer to the following procedures:

•	Air Delivery Description and Operation

•	Air Temperature Description and Operation

•	Inspect for aftermarket devices which could affect the operation of the HVAC System. Refer to Checking Aftermarket Accessories.

•	Inspect the easily accessible or visible system components for obvious damage or conditions which could cause the symptom.

•	Verify the A/C compressor clutch turns freely and is not seized.

•	The A/C compressor will not operate in cold outside air temperatures. Refer to Air Temperature Description and Operation.

•	The following could cause window fogging:

-	Wet carpet or mats

-	High humidity

-	Interior water leak

-	Blocked A/C evaporator drain tube

-	Maximum passenger capacity

-	Blocked body pressure relief valves

•	Inspect the air distribution system for causes of reduced air flow:

-	Obstructed or dirty passenger compartment air filter, if equipped

-	Blocked or damaged air inlet or outlet vents

Faulty electrical connections or wiring may be the cause of intermittent conditions. Refer to Testing for Intermittent Conditions and Poor Connections.

Refer to a symptom diagnostic procedure from the following list in order to diagnose the symptom:

•	Blower Motor Malfunction

•	Air Conditioning Compressor Malfunction

•	Noise Diagnosis - Air Conditioning (A/C) System

•	Noise Diagnosis - Blower Motor

•	Odor Diagnosis