VW Lupo HVAC System Complete Failure Fix Guide

Had a similar issue with a 2002 VW Polo, which shares many components with the Lupo. Coming from someone with moderate experience working on VAG cars, this sounds very familiar. The symptoms matched exactly, unresponsive climate controls and heating/cooling issues. After taking it to my regular workshop, they diagnosed faulty electrical connectors between the blower motor and the control module. The temperature sensor readings were completely off due to a deteriorated wiring harness. The fix involved cleaning all electrical connectors and replacing a section of the wiring that had corroded. Total cost was 95€ including diagnostic time. Electronic faults like this are pretty common in these models as the wiring ages. To give more specific advice about your case, could you share: Does the blower work at all or is it completely dead? Are you getting any air flow, even if not temperature controlled? Which specific fault code is stored? Have you noticed any other electrical issues? The power supply to these components often degrades over time, but knowing these details would help narrow down if your issue matches what I experienced.

Thanks for your detailed input. I should note my mileage is at 19509km with no previous similar issues recorded at services. The blower motor does work but very weakly, and only on the highest setting. There is minimal airflow through all vents. Getting error code P0533 from the climate control unit. No other electronic faults noticed in other systems. Based on your Polo experience and the similar symptoms, it seems checking the wiring and connectors should be my first step. The weak blower response even on max settings does point toward an electrical connection problem rather than a complete control panel failure. Did cleaning the connectors immediately restore full blower function in your case? Or did it take some time for the HVAC system to start working properly again?

Thanks for providing those additional details. The error code P0533 definitely points to an AC pressure sensor circuit issue, which aligns with my previous Polo repair experience. The weak blower behavior you describe is nearly identical to what I encountered, mine also only worked on the highest setting with reduced airflow. In my case, cleaning the connectors provided an immediate improvement in blower performance, but the air conditioning system took about 2-3 starts before functioning normally. Your mileage is surprisingly low which makes me think moisture might have gotten into the wiring harness connections rather than age-related deterioration. The temperature sensor circuits are particularly sensitive to this kind of damage. My repair involved: 1. Cleaning all electrical connections in the HVAC system 2. Replacing a 20cm section of the wiring harness where corrosion had spread 3. Applying dielectric grease to protect against future moisture Given your symptoms match mine so closely, I suggest having the workshop focus on the wiring and connections first before replacing any major components. The climate control issues resolved completely once the electrical connections were restored. One thing I learned, the temperature sensor readings need to be within spec for the air conditioning to activate, even if the rest of the system is working. This is a built-in safety feature of the climate control system.

Thanks for sharing those repair experiences. Your similar situation with the Polo definitely gives me a good starting point. The P0533 code and weak blower symptoms seem very similar to what you encountered. Going to have my regular workshop check the wiring harness and connections first before replacing anything major. Good to know about the temperature sensor readings affecting AC operation, that could explain why the system wont activate at all. Was thinking about trying to clean some connections myself, but given the sensitivity of the control panel system and risk of making things worse, I will leave it to professionals. The repair cost you mentioned seems reasonable if it fixes both the heating and cooling. Will make sure they check for moisture damage in the wiring since the low mileage suggests age isnt the main factor. The dielectric grease application sounds like a smart preventive measure to include while they are working on it. Will circle back with results once the car is checked. Hopefully its just corroded connections like in your case rather than needing a full control panel replacement.