VW Caddy Blower Motor Dead, AUC Sensor Fault Fix

Had nearly the same issue on my VW Golf from 2001, also with a gasoline engine. As someone with moderate experience working on VWs, I can share what helped fix it. The air quality sensor and cabin air sensor setup failed similarly, no blower function and the auto air recirculation stopped working. After trying basic troubleshooting, I took it to a workshop where they diagnosed a loose connection in the BMW AUC-style sensor wiring harness. The fix involved accessing the HVAC sensor array behind the glove box, where they found and repaired a damaged wire connection to the blower control module. Total cost was 95€ including diagnostic time and repair. Before suggesting specific fixes for your Caddy, could you share: Have you noticed any warning lights on the dash? Does the blower respond at any speed setting? Can you hear the recirculation flap moving when switching modes? Has there been any recent work done near the ventilation system? This information would help determine if your issue matches what I experienced with the air conditioning sensor system.

Mileage is 77661km, last service done in February. Thanks for the detailed response. After reading this, I did check for the warning lights, nothing shows up on the dash. The blower is completely dead across all settings and I cant hear the flaps moving at all when toggling the controls. The odor sensor setup in these models seems quite sensitive. Your mention of the wiring harness issue is interesting since I had some work done on the dashboard about 2 months ago. The timing could be related. Before heading to a shop, would it make sense to inspect the HVAC sensor connections myself? I have basic tools and some experience with simple repairs, though accessing the area behind the glove box seems tricky.

Thanks for those additional details. Like I mentioned from my Golf experience, accessing the climate control components behind the glove box is indeed possible but requires careful maneuvering. Since you had recent dashboard work, this strongly suggests a connection issue similar to what I encountered. The auto recirculation and odor sensor system in these VW models share a common wiring path through that area. When technicians remove the dash trim, it's easy to accidentally disturb these connections. In my case, the AUC sensor connector had partially separated, causing both the blower failure and loss of the air flap function. The fact that you can't hear the flaps matches this scenario perfectly. For a DIY approach, you can: 1. Remove the lower dash panel under the glove box 2. Check for any obvious loose or disconnected wiring harnesses 3. Look specifically for the air conditioning sensor cluster connection point However, given the complete system failure and similarity to my situation, a professional diagnostic might save time. The repair itself was straightforward once the actual issue was located, costing around 95€ in my case. Would you like details on the glove box removal procedure to check these connections yourself?

Appreciate the thorough guidance. The AUC sensor symptoms you describe match my situation exactly. After comparing our cases and considering the recent dashboard work timing, I feel more confident about the likely cause now. Since the auto recirculation and blower issues started gradually after the dash work, a disturbed connection makes perfect sense. The complete lack of flap movement and blower response fits with your experience too. I think I will try accessing the area behind the glove box first, following the inspection steps you outlined. If I spot any obvious wiring issues with the air conditioning sensor cluster, I can attempt a fix. Otherwise, knowing it cost you around 95€ for a professional repair gives me a good benchmark. One last question, did you find any specific spots where the wiring tends to get pinched or damaged during dash removal? This could help me focus my inspection on the most likely problem areas when I check the odor sensor connections.