- Preliminary Inspections

IMPORTANT: Review the system operation in order to familiarize yourself with the system functions. Refer to:
- Air Delivery Description and Operation
- Air Temperature Description and Operation
- 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

Visual/physical Inspection
- Inspect for aftermarket devices which could affect the operation of the HVAC System. Refer to Checking Aftermarket Accessories in Diagrams.
- 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.

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

Symptom List
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
- Blower Motor Always On - Auxiliary (W/ Sunroof or Heat Only) or Blower Motor Always On - Auxiliary (W/O Sunroof)
- Blower Motor Inoperative - Auxiliary (W/ Sunroof or Heat Only) or Blower Motor Inoperative - Auxiliary (W/O Sunroof)
- Blower Motor Malfunction Auxiliary (W/ Sunroof or Heat Only) or Blower Motor Malfunction - Auxiliary (W/O Sunroof)
- Too Hot in Vehicle
- Too Cold in Vehicle
- Too Hot in Vehicle - Auxiliary (with Sunroof) or Too Hot in Vehicle - Auxiliary (w/o Sunroof)
- Too Cold in Vehicle - Auxiliary (with Sunroof) or Too Cold in Vehicle - Auxiliary (w/o Sunroof)
- Air Delivery Improper
- Air Delivery Improper - Auxiliary (W/O Sunroof) or Air Delivery Improper - Auxiliary (W/ Sunroof)
- Air Recirculation Malfunction
- Leak Testing in Heating, Ventilation and Air Conditioning Leak Testing
- Defrosting Insufficient in Heating, Ventilation and Air Conditioning Defrosting Insufficient
- High or Low Temperature Control Effort in Heating, Ventilation and Air Conditioning
- Noise Diagnosis - Blower Motor in Heating, Ventilation and Air Conditioning Noise Diagnosis - A/C System
- Noise Diagnosis - A/C System in Heating, Ventilation and Air Conditioning Noise Diagnosis - A/C System
- Odor Diagnosis in Heating, Ventilation and Air Conditioning Odor Diagnosis