BMW Z3 Wiper Switch Gone Haywire, Fix Needed

I had a similar issue with my 2003 BMW Z4 last winter. The wipers started acting up out of nowhere, sometimes not responding, other times going off without any input. Turned out it was a faulty connection in the wiring harness near the steering column, where the wiper control module connects. The mechanic found corrosion on the pins and noticed one of the connectors was loose. The fix involved cleaning the connections and replacing a damaged section of the wiring harness. It wasn't a super serious issue, but leaving it unfixed could've led to other electrical problems. The repair took about 2 hours at the shop. If you're getting an error code, it's likely electrical rather than mechanical. A broken wiper switch would usually just result in non-working wipers, not the unusual activation you're describing. Get the wiring checked first before replacing any parts.

Thanks for sharing your experience! That's really helpful info about the wiring harness. Had a similar repair done myself and it sounds spot on. Can't remember what they charged me though, do you remember what you paid for the fix? Also, just curious, have you had any other electrical gremlins pop up since getting it repaired? My BMW's getting up there in age so I'm trying to stay ahead of potential issues.

Hey there! Glad I could help with the wiring harness info. Yeah, I actually just had this fixed last week, cost me 95€ to repair that pesky cable connection issue. The mechanic found the problem pretty quickly and sorted it out. Since getting it fixed, the wipers have been working perfectly, no more unusual activations or failing to respond. As for other electrical issues, I've been pretty lucky with my Z4. Haven't had any other gremlins pop up since the repair. But you're right to think ahead with these older BMWs. I keep an eye on things like the window regulators and door locks since they can sometimes act up with age. The good news is that once you get these electrical niggles sorted properly, they usually stay fixed. Just make sure you get a mechanic who knows their way around BMW electronics, it makes a huge difference. Mine definitely earned their money by finding that faulty connection instead of just replacing parts unnecessarily.

Thanks so much for the detailed follow-up! Just got back from my mechanic today actually. You were totally right, it was an electrical issue, but in my case, it was a corroded ground wire connection near the firewall. Cost me a bit less than yours, around 80 for parts and labor. What a relief it wasn't anything major! The mechanic I found this time actually specializes in BMW electronics. He walked me through the whole repair process and even showed me the corroded bits. Such a different experience from my last mechanic who just wanted to replace the entire wiper motor without even checking the wiring. The wipers are working perfectly now, no more ghost movements or complete failures. Keeping my fingers crossed that's the end of my electrical issues for a while. Thanks again for pointing me in the right direction with this!