Visual/Physical Inspection

Inspect for aftermarket devices which could affect the operation of the HVAC system. Inspect 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.

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 proper air flow/distribution:

• Blocked or damaged air inlet or outlet vents.
• Blower motor operation in all speeds.
• Equal distribution of air out of all the outlets.
• Control mode knob and distribution of air from the designated outlets.

Inspect the following for a lack of A/C performance:

• Air inlet duct, lower air deflector, condenser to radiator seal, and rear hood seal for missing or damaged parts. Also, the outer surfaces of the radiator and condenser cores, to ensure the air flow is not blocked by dirt, leaves, or other foreign material. The importance of checking for proper front air flow cannot be stressed enough because proper heating and cooling depends upon adequate front air flow.
• Kinks in the hoses and lines. Also check for refrigerant leaks.
• Worn or loose drive belt or malfunctioning belt tensioner.
• Electric cooling fan operation with the A/C on and engine at normal operating temperature.
• Compressor clutch engagement, slippage, or noise.
• Operation of the temperature control knob and the air outlet temperature from hot to cold.

If any problem is found, correct condition as necessary or see SYMPTOM TESTS .