BMW Z3 A/C Dead? Common Causes and Solutions

I had a similar issue with my 2004 BMW Z4 last summer. The A/C completely died, and the scan showed an undervoltage code. Initially thought it was just the compressor like you did, but turned out the problem was more complex. When I took it to the garage, they found that the A/C relay had failed, which was causing the compressor not to engage at all. They also discovered corrosion on the electrical connectors leading to the compressor clutch. This was causing intermittent power supply issues. The fix involved replacing the relay, cleaning all electrical connections, and replacing some worn wiring. The mechanic also checked the refrigerant level while they were at it. It wasn't a super serious issue, but leaving it unfixed could have eventually damaged the compressor. Since the repair, the A/C has been working perfectly. Based on your symptoms, I'd suggest getting the electrical system checked first before assuming it's a compressor issue. Sometimes these problems aren't as major as they seem, but you definitely want a thorough diagnosis.

Thanks for sharing that detail about your Z4! It's really helpful to know about the relay and electrical issues you found. That's making me feel a bit more optimistic about my situation. Do you remember roughly how much the whole repair set you back? Also, has everything stayed working properly since then, or have you noticed any other cooling problems pop up?

Hey again! Just wanted to update you on my Z4 situation. After my last post, I actually took it back to the mechanic to fix the A/C compressor shut-off issue. The whole thing cost me 240 € for fixing the undervoltage problem, and I've got to say it was totally worth it. The A/C has been working like a dream since then, no more problems at all! It's funny you asked about other cooling issues because I was a bit worried about that too, but honestly, everything's been running smooth as silk. The system's keeping me nice and cool even on those scorching hot days. Looking back, I'm really glad I didn't jump to conclusions about needing a whole new compressor. Sometimes these electrical gremlins can make things seem way worse than they actually are. Trust me, getting it properly diagnosed was the way to go. I know dealing with car issues can be a pain, but once you get it sorted, it's such a relief. Let me know how yours works out!

Hey! I really appreciate you following up! You won't believe it, but I finally got my car checked out today. Turns out my issue was pretty similar to yours, mainly electrical problems rather than a completely dead compressor. The mechanic I found was actually really decent and walked me through everything. Fixed the faulty connections and replaced a blown fuse that was causing the system to fail. The whole thing came to about half what I was expecting to pay, which was a massive relief after thinking I'd need a new compressor! The A/C is now blasting cold air like it's brand new. Getting burned by that previous mechanic made me super cautious, but your story really helped me take the plunge and get it looked at properly. Thanks again for sharing your experience, it definitely saved me from spending way more than I needed to. Really glad I asked for advice here before jumping to conclusions!