- Symptoms - HVAC Systems - Manual

Symptoms - HVAC Systems - Manual

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

Visual/Physical Inspection

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

Intermittent

Faulty electrical connections or wiring may be the cause of intermittent conditions.

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
* Too Hot in Vehicle
* Too Cold in Vehicle
* Air Delivery Improper
* Leak Testing in Heating, Ventilation and Air Conditioning
* Defrosting Insufficient 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