Symptoms - HVAC Systems - Automatic

Symptoms - HVAC Systems - Automatic

Note:
Review the system operation in order to familiarize yourself with the system functions. Refer to: Automatic HVAC Description and Operation (LHD) Automatic HVAC Description and Operation (LHD)

Visual/Physical Inspection

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

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

* Verify the A/C compressor turns and is not seized.

* The A/C compressor will not operate in cold outside air temperatures. Refer to Automatic HVAC Description and Operation (LHD) Automatic HVAC Description and Operation (LHD).

* 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:

Blocked or damaged air inlet or outlet vents.

Intermittent

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

Symptom List

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

* Air Temperature Malfunction Air Temperature Malfunction.

* Air Conditioning (A/C) System Performance Test Initial Inspection and Diagnostic Overview.