Symptom Table

Symptoms - HVAC Systems - Maunual

Important: Review the system operation in order to learn the system functions.

^ 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. Refer to Checking Aftermarket Accessories in Wiring Systems.
^ Inspect the system components which are easily accessible or visible for obvious damage or for 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:

- A wet carpet
- High humidity
- An interior water leak
- A blocked drain tube to the A/C evaporator
- Maximum passenger capacity
- Blocked body pressure relief valves

^ Inspect the air distribution system for causes of reduced airflow:

- An obstructed or dirty passenger compartment air filter
- Blocked or damaged air vents

Intermittent

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

Symptom List

Refer to one of the following symptom diagnostic procedures:

^ HVAC Compressor Clutch Does Not Engage Compressor Clutch Does Not Engage
^ HVAC Compressor Clutch Does Not Disengage Compressor Clutch Does Not Disengage
^ Blower Motor Always On Blower Motor Always On
^ Blower Motor Inoperative Blower Motor Inoperative
^ Blower Motor Malfunction Blower Motor Malfunction
^ Too Hot in Vehicle Too Hot In Vehicle
^ Too Cold in Vehicle Too Cold in Vehicle
^ Air Delivery Improper Air Delivery Improper
^ Air Recirculation Malfunction Air Recirculation Malfunction
^ Leak Testing in Heating, Ventilation and Air Conditioning Leak Testing
^ Defrosting Insufficient in Heating, Ventilation and Air Conditioning Defrosting Insufficient
^ Noise Diagnosis - Blower Motor in Heating, Ventilation and Air Conditioning Noise Diagnosis - Blower Motor
^ Noise Diagnosis - Air Conditioning (A/C) System in Heating, Ventilation and Air Conditioning Noise Diagnosis - Air Conditioning (A/C) System
^ Noise Diagnosis - HVAC Module in Heating, Ventilation and Air Conditioning Noise Diagnosis - HVAC Module
^ Odor Diagnosis in Heating, Ventilation and Air Conditioning Odor Diagnosis