EQC air conditioning failure

That is a frustrating situation. When you checked the pressure switch, did you verify the refrigerant pressure using a manifold gauge set? A low refrigerant level, even if the switch appears functional, can prevent the compressor from engaging. Also, have you tried manually engaging the compressor to see if it activates? It could be an issue with the temperature control module not sending the signal.

Thank you for the suggestions. Regarding the pressure switch, I only visually inspected it. I do not possess a manifold gauge set to measure the refrigerant pressure directly. Could a faulty temperature control module prevent the system from activating even if the refrigerant level is adequate? How would I manually engage the compressor for testing purposes?

Yes, a faulty temperature control module absolutely could prevent the AC from activating, even with sufficient refrigerant. As for manually engaging the compressor, that is often best left to a trained technician because forcing it could damage other components. Given you lack the manifold gauge set and the potential complications, it might be prudent to have a workshop perform a proper diagnostic. They can check for refrigerant leaks, test the compressor clutch, and assess the temperature control module's functionality. It sounds like AC maintenance might be due anyway.

I appreciate the advice. I suspected as much, given the complexity. I will schedule an appointment with a qualified technician to diagnose the system thoroughly. Your input regarding the temperature control module and the potential risks of manual compressor engagement was particularly helpful. The repair cost was 1000€. Thank you again.