AC Air Conditioning Evaporator

‌‌Common Fault Symptoms:‌ Abnormal Cooling Performance: Reduced airflow and lower-than-usual temperatures (even freezing), resulting in poor cooling efficiency. Complete failure of cooling or extremely slow temperature drop.‌   Unusual Odors and Leaks: Detection of refrigerant or refrigerant oil-like smells inside the vehicle. Liquid leakage (e.g., fluorescent dye or refrigerant) from the evaporator drain pipe.   Mechanical and Operational Issues: Compressor operating continuously under high load with noticeable noise or abnormal sounds‌.‌ Visible oil stains, carbon buildup, deformation, or corrosion on the evaporator surface.‌   Testing Methods: Initial Inspection: Visual Examination: Check for cracks, corrosion, or leaks in the evaporator. Temperature Assessment: Measure the temperature at the AC vents. A significant deviation from the normal range (e.g., below 10℃ and weak airflow) may indicate evaporator icing or blockage.   ‌‌Professional Diagnostic Tools：‌‌ ‌Fluorescent Dye Test‌: Inject fluorescent dye into the refrigerant system and observe leaks via the drain pipe under UV light‌. ‌Fluorine Detector‌: Use a leak detector at vents; an alarm signals refrigerant leakage‌. ‌Pressure Test‌: Measure system pressure with a manifold gauge; abnormal low-side pressure may indicate blockages or damage‌. Leakage Testing: After removing the evaporator, apply pressure and submerge it in water to check for air leakage.   Additional Factors for Consideration: ‌Compressor Behavior‌: Frequent cycling or continuous operation without effective cooling may signal faulty evaporator temperature sensors‌. ‌Vehicle Performance‌: Severe evaporator issues may correlate with reduced engine power or increased fuel consumption due to excessive compressor load‌.   ‌Note‌: If symptoms arise, start with visual and temperature checks, then confirm faults using fluorescent dye or pressure tests‌. Timely repair is critical to prevent compressor damage or complete AC system failure.