BMW 7 Series Power Windows Dead, Help Diagnosing Issue

Hey there! I've got some experience with BMWs, I own a 2015 BMW 5 Series diesel, and I've had my share of electrical issues. Funny enough, I faced almost the same problem last month. The power windows stopped working completely, and the system was showing error codes. Initially, I thought it was the window regulators too, but it turned out my car battery was dying. These luxury cars are super sensitive to voltage drops, and when the battery starts failing, electrical systems like windows are usually the first to act up. Took it to my regular workshop, and they diagnosed it right away. After replacing the battery (cost me 290 Euro), all the electrical systems, including the windows, started working perfectly again. Can you share if you're noticing any other electrical issues? Like flickering lights or slow starter motor? Also, when was the last time you replaced your battery? This info would help figure out if you're dealing with the same problem. I've got a 530d, by the way. The 7 Series and 5 Series share quite a few electrical components, so our issues might be similar.

Thanks for sharing that! My 7er just hit 121223 KM and had its last service about two months ago. Actually, now that you mention it, I have noticed the starter seems a bit sluggish lately, especially during cold starts. The battery is still the original one from 2013, so you might be onto something there. I was really worried it'd be something more serious with the window regulators, but this makes a lot of sense. I'll definitely get the battery checked first before diving into more complex repairs. Did you notice any warning lights before your battery completely gave up?

Hey again! Thanks for the additional info about your 7er. Yeah, that original battery from 2013 is definitely pushing its luck, they typically last around 5-7 years in these BMWs. Mine didn't show any warning lights until it was really on its last legs, which is pretty typical. These cars can be sneaky that way! The sluggish starter you mentioned was exactly what I experienced too. I actually waited a bit too long before replacing mine, and one morning, the car just wouldn't start properly. Talk about a wake-up call! The funny thing is, right before that happened, I noticed the windows would sometimes work fine in the morning but act up later in the day. It's like the battery was giving its last hurrah. If your battery is the original one from 2013, I'd strongly recommend getting it replaced before you end up stranded somewhere. These modern BMWs are pretty power-hungry, and a weak battery can cause all sorts of weird electrical gremlins. Trust me, I learned that the hard way! Since you're around 121K km, it might be worth doing a full electrical system check while they're at it. Better safe than sorry, right? Let me know what you find out, I'm curious if it turns out to be the same issue as mine.

Thanks so much for that detailed response! Yes, I think I better not tempt fate with this old battery anymore. You're absolutely right about these cars being power-hungry, I've noticed more quirks recently that I didn't connect until now. The radio has been resetting its settings occasionally, and the climate control seems a bit erratic too. I just called my regular mechanic and scheduled an appointment for tomorrow morning. They'll do a full electrical system check and battery replacement if needed. Really appreciate you sharing your experience, you've potentially saved me from a much bigger headache! I was already imagining having to replace all four window regulators, which would've been a much more expensive fix. I'll update the thread once I get it sorted. Thanks again for helping me dodge what could've been a real hassle!