BMW 525i won't turn over. No Noise No Click...Nothing

HI,
I am new to this forum, and am not a mechanic. My car was fine, I went into a restaurant for about an hour, and left my lights on. When I tried to start the car, there was no click, no noise of any kind, and the car won't start.
I had a friend come an jump it, but still would not start. The battery seems fine. The windows work, the lights come on bright, but when you turn the key...NOTHING!
I called AAA and they came to take it to my home. The driver used a portable charger, and tried to charge it with a positive connection under the hood. Still would not work. He suggested it was not the starter, or coil, because there was no noise. He thinks the car is being told not to work. Some system that BMW has that he knows nothing about. He suggested maybe there is a "battery saver" switch, or something like it that needs to be told to let the car turn over.
I have read the forums, but am confused.
Does anyone have any ideas?
Thanks so much!

Did you check all of your fuses? How about the fuseable link under the rear seat behind the battery? Start with the basics and go from there. Check the wiring on the battery. A loose wire will cause these cars to go bonkers. Grab a Bentley manual so you can use that to help get you started.

I would try to jump start the car again, this time dont use a portable jump pack. They often times don't have enough juice, so use another car and some jump cables. Make sure you have a good connection.

If none of the above works, I would suggest you take the battery out and take it to a local parts store (AutoZone, Advance Auto, etc.) and have it load tested. I suspect your battery is bad. These cars are very tempermental and require a fully charged battery to operate correctly.

Let us know what you find out when you get it fixed .... and I know you will.

Steve

Thanks for your help. We put a new battery in...my old one was 9 years old. That did not work.
Then we checked the fuse, found one broken, replaced it and it worked!
Thanks to everyone...

Glad you got it fixed. If the battery was 9 years old, it was time for a new one anyway.

Which fuse by the way?

Steve

Yeah, get back here and tell us which fuse you fixed in order to solve your problem, so that others may benefit from your experience.

I had the same problem a couple of days ago. Drove car to work, but when I went back to run an errand it wouldn't start. Towed it to my mechanic and it started. So strange. Anyway, they tested it and found that my battery was very weak. I bought my 325i brand new in 2005, so it was time for a new battery.

I'm thinking battery failure.

same thing just happened to me. turned out to be a fuse for the "engine control" which on my car is in the 29 and 30th position.

I had the same problem with my 1990 525i and it turned out to be related to my anti-theft device. When using just my key to open the door and start it, it wouldnt crank. But when clicking my remote and disarming the alarm it worked fine. Seemed odd to me, i was thinking it might be your issue but glad to see you got it fixed.

I thought it was the same problem i had lol. I had to do an ews bypass. Wich is not easy, mind you.