Preliminary Inspection
WARNING: This page is about a different car, the 1999 Ford Expedition. However, it is still accessible from the selected car via links, so may be relevant.
- Verify customer complaints by operating system in all available modes. Carefully check the following for possible cause of problems and repair as necessary: damaged vacuum hoses, system components, damaged compressor drive belt, open fuses, damaged/misrouted wiring circuits, and damaged/disconnected connectors.
- Check for small leaks in vacuum circuit. Test vehicle with engine running and accelerate engine while checking airflow. During acceleration, all airflow will suddenly go to defroster outlets, indicating a small leak.
- While checking vacuum hoses, DO NOT pinch hoses to stop vacuum flow. Instead, plug hoses with wooden golf tee for testing. Vacuum hose material will not withstand pinching.
- If problem remains after preliminary inspection and any repairs have been made, go to SYMPTOM DIAGNOSIS .