VW Golf TDI AC Complete Failure, Diagnosis Needed

I had a very similar issue with my 2014 VW Passat TDI last summer. After running basic AC diagnostics, my local workshop identified defective valves in the air conditioning system that were preventing proper operation. When the AC system first stopped working, there was no response from the temperature control unit and zero airflow, exactly like your symptoms. The cooling system valves had failed completely, preventing the blower motor from engaging. The total repair came to 1000€, which included: Complete valve replacement, System pressure testing, Refrigerant recharge, Labor costs Before you proceed with repairs, it would help to know: Are you getting any error codes? Did the AC failure happen suddenly or gradually? Do you hear any unusual AC noise when trying to activate the system? Has the car had any previous AC work done? As someone with moderate experience working on VWs, I would strongly recommend getting a proper diagnosis before replacing parts. These symptoms can have multiple causes in VAG vehicles, and targeted repairs will save money versus trial and error.

Thanks for sharing your experience. My mileage is at 29024km and had the last service 3 months ago. No error codes showing on the dash. The AC stopped working suddenly during a drive, complete failure with no warning signs. The blower motor is completely dead, no sound at all when pressing the AC controls. The AC relay and pressure switch were checked during the last service and were working fine then. No previous AC repairs on this car. Would start with checking the fuses and electrical connections before diving into more complex AC system repairs. Any specific components you suggest looking at first based on your experience?

Thanks for those extra details. Your situation sounds almost identical to what happened with my Passat, especially the sudden failure without warning signs. After my experience, I would first verify the AC relay since electrical components can fail even shortly after being checked. The complete silence from the blower points strongly toward an electrical issue rather than a mechanical AC problem. In my case, despite the previous service check, the pressure switch ended up being faulty. These can deteriorate quickly and cause the temperature control system to shut down completely as a safety measure. Quick checks to perform before deeper repairs: Fuse box inspection (both under hood and dash), AC relay function test, Pressure switch connections, Blower motor wiring harness The good news is if its electrical, repair costs typically range from 200-400€ versus the 1000€+ for major AC system work. The workshop should be able to diagnose the exact cause with proper testing equipment. Given your low mileage and maintenance history, I would be surprised if this requires a complete AC system overhaul like mine did. The symptoms really point toward an electrical control issue rather than a mechanical failure.

Thank you for the detailed response. Based on your suggestion, I will focus on the electrical components first since that seems the most likely culprit. The complete silence and sudden failure does match what you experienced with your electrical issues. I will have the workshop run full AC diagnostics but will ask them to specifically check: All fuses and AC relay connections, Pressure switch functionality, Blower motor wiring, Overall AC efficiency through their testing equipment 200-400€ for an electrical fix sounds much better than a full system repair. Since the AC maintenance was good at the last service, hopefully this is just a faulty switch or relay causing the system shutdown. Will book it in next week and request they start with electrical testing before looking at any mechanical components. Really helpful to know the pressure switch can fail quickly even after being checked. At least there is a clear starting point for the diagnosis now rather than replacing parts out of nowhere. Looking forward to having working AC again, definitely worth getting proper AC diagnostics rather than guessing at the problem.