VW Lupo AC Failure: DIY Tips & Mechanic Warning

As a VW Golf TDI 2001 owner, I encountered nearly identical AC symptoms last season. The complete AC system shutdown often points to either the AC relay failure or a faulty pressure switch, both being common issues on VW models from that era. During AC diagnostics, the technician discovered the pressure switch had failed, which is a safety feature that shuts down the system when refrigerant pressure becomes too high or low. This was causing the temperature control system to remain completely unresponsive. The pressure switch replacement itself was relatively straightforward, but they also found a leaking Schrader valve during testing. These valves can deteriorate over time, especially in vehicles of this age. Left unchecked, this could have led to a complete loss of refrigerant and potential compressor damage, a much more serious repair. Recommend having a qualified technician: Test the AC relay, Check refrigerant pressure levels, Inspect all Schrader valves, Verify pressure switch operation, Run a complete system leak test While not a catastrophic issue if caught early, ignoring these symptoms could lead to more expensive components failing. The VW Lupo shares many AC components with other VW models of that generation, so parts availability shouldnt be an issue.

Thanks for sharing your experience with the AC system failure. The steps you outlined were really helpful. My AC has been fixed now and the blower motor is working perfectly again. The mechanic also mentioned the AC relay was indeed the culprit, just as you suspected. Would you mind sharing how much the total repair cost was in your case? Also curious if youve had any temperature control issues since the fix? My mechanic mentioned something about checking AC efficiency again after a few months.

Great to hear your AC system is working again! My repair experience was quite similar, with the AC relay being the root cause of the problem. The final cost in my case was around 1000€, which covered replacing some defective valves in the air conditioning system. Since the fix, the temperature control has been perfect and the AC efficiency remains excellent even after heavy use. The blower motor now runs smoothly without any AC noise issues that were present before the repair. Its actually good practice to have the AC checked periodically, I usually get mine inspected during regular maintenance to catch any potential issues early. This helps maintain optimal AC efficiency and prevents more expensive repairs down the line. If youre monitoring your system post-repair, pay attention to any unusual sounds or changes in cooling performance. But from my experience with these VW models, once properly fixed, the AC system tends to remain reliable for years.

Thanks for the advice. I went ahead and got it checked out at a local shop that specializes in VW cooling systems. The total repair came to 850€, which included replacing the AC relay and a thorough system inspection. The mechanic explained that my temperature control issues stemmed from a combination of a faulty relay and low refrigerant levels affecting the pressure switch operation. The AC diagnostics revealed no other major problems, which was a relief. Since the repair last month, the AC has been working flawlessly, cold air blows strong and the system kicks in immediately. I also learned my lesson about regular maintenance. The shop recommended annual AC efficiency checks, which seems worth it to avoid another complete system failure. For anyone else with similar issues, definitely get it checked early. The peace of mind knowing everything is working properly is worth the investment, and catching problems early saved me from more expensive repairs down the line.