Symptoms - HVAC Systems - Manual. GMC Truck Yukon

For 1990-2009 cars only

Makes 🢒 GMC_Truck 🢒 2005 🢒 Yukon - 2WD 🢒 General Information 🢒 Vibration Diagnosis and Correction 🢒 Symptoms - HVAC Systems - Manual

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

•	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 in Wiring Systems.

•	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 conditions may 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 in Wiring Systems.

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

•	HVAC Compressor Clutch Does Not Engage

•	HVAC Compressor Clutch Does Not Disengage

•	Blower Motor Always On

•	Blower Motor Inoperative

•	Blower Motor Malfunction

•	Auxiliary Blower Motor Always On

•	Auxiliary Blower Motor Inoperative

•	Auxiliary Blower Motor Malfunction

•	Too Hot in Vehicle

•	Too Cold in Vehicle

•	Too Hot in Vehicle - Auxiliary

•	Too Cold in Vehicle - Auxiliary

•	Air Delivery Improper

•	Air Delivery Improper - Auxiliary

•	Air Recirculation Malfunction

•	Leak Testing in Heating, Ventilation and Air Conditioning

•	Noise Diagnosis - Blower Motor in Heating, Ventilation and Air Conditioning

•	Noise Diagnosis - Air Conditioning (A/C) System in Heating, Ventilation and Air Conditioning

•	Noise Diagnosis - HVAC Module in Heating, Ventilation and Air Conditioning

•	Odor Diagnosis in Heating, Ventilation and Air Conditioning