VW Fox Climate Control Dead, Heating & AC Malfunction

Had almost the exact same issue with my 2007 VW Polo diesel last winter. I have some experience with basic car maintenance, but HVAC system problems were beyond my skill level. The symptoms matched yours perfectly, unresponsive control panel and the air conditioning system completely dead. The blower motor would occasionally work but the heating was minimal. Took it to a workshop where they diagnosed faulty electrical connectors between the control panel and the HVAC system. They found corroded pins in the main connector which caused intermittent connections. The repair involved cleaning the connections and replacing one damaged connector. Total cost was 95€ for parts and labor, which seems reasonable given the diagnostic work needed. The fix has lasted over a year now with no issues. Before suggesting more specific solutions, could you share: Have you noticed any other electrical issues? Does the blower motor work at all? Are there any specific error codes showing? Has there been any recent work done on the HVAC system? This information would help determine if your issue is similar to what I experienced or something different.

Thanks for checking. My car had its last service at 51000km about 2 months ago. The blower motor works intermittently, sometimes at full power, other times not at all. No other electrical issues noticed. Getting error codes P0531 and P0532 from the system. The power supply to the control unit seems unstable based on the diagnostic readout. The wiring harness looks intact from what I can see, though there might be hidden damage. No prior work has been done on the climate control or air conditioning system since I bought the car. Would you recommend checking the connectors first before considering a full control unit replacement?

Thanks for those details. Your situation sounds even more similar to what I faced now that you mention the error codes and intermittent blower behavior. The P0531 and P0532 codes typically point to AC pressure sensor circuit issues, but in my case these were actually symptoms of poor power supply to the control unit, just like yours is showing. The unstable power readings are a strong indicator that electrical connections are the primary issue. Checking the connectors would definitely be the smart first step. In my repair, the workshop found the culprit was corrosion in the main wiring harness connector that feeds the HVAC system control unit. The intermittent blower behavior is nearly identical to what I experienced, it turned out the corroded pins were causing voltage drops. A few things to note from my experience: The electronic faults cleared up immediately after the connector repair, Full control unit replacement would have cost around 450€, The actual connector repair was just 95€, The air conditioning system started working properly once power was stable The power supply issues you mentioned are particularly telling. I would strongly recommend having the connectors inspected and cleaned before considering more expensive components. The workshop should be able to access and check these without major disassembly. Just verify they do a thorough check of all HVAC system connectors, not just the obvious ones at the control panel.

Thanks for all the input. I am getting the connectors checked first, makes total sense to start with the simpler solution considering the similarity of symptoms and those electronic faults. Booked the car in for next week. The shop agreed the wiring harness and electrical connectors should be inspected before considering a full HVAC system control unit replacement. They will do a complete power supply diagnostic as well. Will let you know how it turns out, especially if it ends up being corroded connections causing these issues. The error codes and intermittent blower behavior seem to point that way. Hopefully looking at a repair bill closer to 100€ rather than 450€ for a new control unit. Really appreciate the detailed feedback on your similar experience. It helped narrow down the likely cause and saved me from potentially unnecessary expensive repairs.