BMW Z3 Power Window Failure: Fixes and Common Causes

Hey there! I have some experience working on cars and had a similar issue with my 1998 BMW M3. The symptoms were exactly the same, power windows completely dead. Took it to my regular workshop and they diagnosed it as a faulty power window switch. The repair was straightforward and cost me around 200 Euro. The switch had corroded internally, which is pretty common on these older BMWs. Could also be the regulator like you mentioned, but starting with the switch is usually cheaper. Before you head to the shop, have you checked if both windows aren't working or just one? Also, can you hear any clicking sound when pressing the switch? Let me know the specific symptoms and whether it's affecting one or both windows, might help pinpoint the exact issue.

Thanks for sharing your experience! My Z3 has only 37443 KM since I've owned it and was serviced last month. Both windows are completely dead, no clicking, no movement, nothing at all when pressing either switch. I've been keeping up with maintenance, but electrical gremlins seem to pop up regardless. Did your switch show any obvious signs of corrosion before it failed completely? I'm hoping it's just the switch like in your case, as that would be the easier fix. I checked the fuse and that's good, so I'm guessing it's either the switch or regulator at this point.

Hey again! Back to share more about my experience with those pesky BMW electrical issues. Yeah, mine acted exactly the same way, both windows completely dead with no sounds whatsoever, just like yours. Before my switch failed completely, I didn't notice any obvious signs of corrosion. Everything looked fine from the outside, which made it pretty frustrating to diagnose. One thing I learned during the repair, even with regular maintenance, these switches can still fail due to internal corrosion that builds up over time. Since your symptoms match mine exactly (both windows, no clicking, total silence), I'm even more convinced it's probably the switch assembly. When they took mine apart at the shop, the contacts inside were pretty corroded despite the switch looking perfectly fine externally. Here's a pro tip from my experience, before you replace the regulator, definitely get the switch tested first. I almost went down the regulator route myself and would've spent way more money unnecessarily. The switch is usually the culprit when both windows fail simultaneously like this. Keep us posted on what you find out. I'm curious to know if yours turns out to be the same issue as mine!

Thanks so much for the detailed follow-up! Your experience is super helpful, especially knowing that your switch looked fine from the outside despite being corroded internally. That's really good to know. I've just scheduled an appointment with my mechanic for next week and specifically asked them to check the switch assembly first before looking at the regulators. You've probably saved me a bunch of money here! It's really reassuring to hear that your symptoms matched mine exactly before finding out it was the switch. I was getting worried it might be something more serious, but this gives me hope it'll be a relatively straightforward fix. Will definitely update the thread once I get it sorted out. Really appreciate you taking the time to share your experience in such detail!