BMW M3 Wiper System Failure: Diagnosis & Cost Guide

Hey there! I had a similar issue with my 2004 BMW M5 last winter. The wipers completely stopped working, and I got error codes too. Initially thought it was just the relay, but when I took it to the garage, turned out the wiper motor's wiring harness had corroded connections and some damaged pins in the main plug. The mechanic showed me how the connection points were all green and crusty. Not a catastrophic problem, but definitely needed proper attention. They had to replace the entire wiring harness and clean up the connector points. Pretty straightforward fix once they identified the real issue. If your symptoms are similar (complete wiper failure, error codes), I'd bet you're dealing with the same problem. While the relay could be the culprit, those wiring harness issues are pretty common on these models. Best to have a proper diagnostic done rather than just swapping parts. Good luck with the fix!

Hey, thanks so much for sharing your experience! That's really helpful. Sounds very similar to what I'm experiencing. Mind if I ask how much you ended up paying for the harness replacement and cleanup? Also, has everything been working fine since the repair? Just want to make sure I'm prepared for what might be coming my way with this fix. Cheers!

Hey there! Good news, my issue actually turned out to be simpler than the harness problem I initially described. Just got back from the mechanic last week and it was indeed just a faulty relay like you suspected. There was a bad cable connection that needed fixing, but nothing major like I experienced with my previous electrical issues. The total came to 95€, way less than I was worried about! And yes, the wipers have been working perfectly since the repair. They're as good as new now, both on manual and auto settings. No more error codes either. Much better outcome than my previous wiring harness drama! Sometimes the simplest explanation is the right one. Hope this helps give you a better idea of what you might be looking at. Let me know how it goes with yours!

Thanks again, what a relief to hear that! Just got back from my mechanic today actually. You were spot on about keeping it simple. Turned out to be just a loose connection and a blown fuse that needed replacing. Total bill came to about 120 bucks including labor, much better than I was expecting! The mechanic this time was really transparent, showed me exactly what was wrong, and fixed it while I waited. Such a different experience from my last repair nightmare. The wipers are working perfectly now, and the error code's gone too. Guess I was overthinking it with the whole relay issue. Really appreciate you taking the time to share your experience. It definitely helped me feel more confident about getting it checked out. Sometimes these BMW issues aren't as scary (or expensive) as we think they'll be! Thanks again!