VW Polo A/C Compressor Failure: Diagnosis and Fixes

Similar issue occurred on my 2012 VW Golf 1.4 TSI. The A/C compressor stopped engaging, matching your symptoms exactly. The diagnostic revealed an undervoltage condition affecting the relay switch of the A/C system. The root cause turned out to be a combination of issues: Faulty pressure sensor sending incorrect signals, Damaged belt tensioner causing irregular compressor operation, Worn electrical connections at the A/C compressor clutch The A/C system requires proper voltage to engage the compressor clutch. When voltage drops below threshold, the system defaults to a safety mode, preventing compressor engagement. This proved to be a serious issue requiring immediate attention, as continuing to run the system with these faults risks damaging the A/C compressor entirely. The repair involved: Replacing the pressure sensor, Installing a new belt tensioner, Reconnecting and securing electrical components, Testing system pressure after repair Your symptoms strongly suggest similar electrical issues. Get it checked soon, as driving with a malfunctioning A/C system can lead to more extensive damage.

Thanks for sharing your experience. The issues with my Polo A/C turned out very similar to what you described. The mechanic found the AC relay was stuck and the pressure switch needed replacement. The system works perfectly now. Would you mind sharing what the total repair cost was in your case? Also curious if you experienced any related issues since the fix?

After getting the undervoltage issue fixed at the shop, my A/C compressor has been working flawlessly. The total repair came to 240€, which included diagnosing and fixing the electrical problems in the HVAC system. The belt tensioner was actually fine in my case, so that helped keep costs down. The main focus was correcting the electrical connections and installing a new pressure sensor. The A/C system has maintained perfect cooling performance for the past 8 months with no warning lights or error codes. Good to hear your Polo had similar symptoms and got sorted out. These electrical gremlins in the A/C system can be tricky to diagnose, but once properly fixed, they typically stay resolved.

Glad I got this sorted out, wanted to share how it went down. Took the Polo to a specialist shop last week and they diagnosed it properly. The AC relay was stuck and the pressure switch needed replacing in the HVAC system, just like others mentioned. Total bill came to 180€ including parts and labor, which felt reasonable. The A/C compressor kicks in right away now and the cooling is working perfectly. No more warning lights or error codes. Really relieved it wasnt a major refrigerant leak or complete compressor failure like I initially feared. The repair took about 3 hours and the mechanic walked me through everything they found. Should have dealt with this sooner instead of worrying about potential high costs. The shop did a great job and now I know exactly what was wrong. Thanks for all the helpful input that helped me understand the issue before taking it in.