What are the reasons for the Audi A4L air conditioning pump not working?

[Dallas]

Audi A4L air conditioning pump not working can be caused by many reasons, one possible reason is the tripping of the compressor protection device. Overload protection of the compressor will trip when the system's high pressure is too high or the current is too hot. Reasons and solutions for high pressure and overheating: Excessive refrigerant. Appropriately reduce the refrigerant amount. Poor heat dissipation. Check if the condenser tube is dirty and clean the condenser. Blockage in the pipeline system. Refer to the pressure gauge to diagnose and resolve, then reprocess the system. Dust and scale accumulation on the evaporator or filter. Reduced airflow causes imbalance in system pressure and temperature; clean the evaporator or filter. Lack of refrigerant is also possible. When refrigerant is insufficient, the compressor's exhaust temperature will overheat, causing the thermal overload protection switch to trip. Electrical circuit issues include: Control circuit board failure. Temperature sensor overload, causing incorrect information. Loose or poor contact in power wiring. Burnt-out start capacitor or compressor start coil.