radio stays on after removing key

[food_yum]

When I got this 2007 M5, it was simple: I took the key out of the ignition, the radio turned itself off. Immediately. A few months later (I got it in 2010), it would keep the radio playing for one minute after removing the key. After that minute, the radio would turn off. The display would stay on a couple of seconds longer than that, but not much.
I know other cars do that, but not in the same way. In this case, the radio STAYS on for the full minute, no matter if the doors are opened, closed, or if there's anyone in the van. If I powered off the radio with the on/off/volume knob, it would turn off without issue. No delay.

The buggy thing is that this is a "flexible situation". It will be like this for months on end, and then one day it will return to the immediate "turn off" it did when I bought it. And then back again to the one-minute delay.

I can't figure out why it does this or what triggers it to switch from one state to the next. Any ideas? Ghosts in the machine? Sould I be worried?

thanks in advance.

 

[Davicho]

I think I know what your issue is. You need to replace your ignition switch with a new updated one. From what I understand the faulty switch stays stuck open. I bet that when this is happening if you pull out the key and open the door the chime goes on as if the key it is still in the ignition. You will also not be able to lock or unlock with the keyfob and the dome lights will not go on. Try it and see or just simply replace the ignition switch it's a cheap and easy fix. I had to do it to mine.

 

[food_yum]

It doesn't do any of that, actually. No chimes etc, it knows the key is out and it doesn't care. It's just a slow powering down of the radio, of sorts. After the radio goes silent, the display remains lit for 5 seconds and ten seconds after that, the clock turns off.

weird. I wish I had a dealer around here to ask questions; the nearest one is 2.5 hours drive away!

 

[Silentnoise713]

Since you bought the car used it could be anything. Do you know if any electrical mods were done to the car (RAP mod?)? Did it have a previous radio or capacitor that might be crossed wired? Are you using an AC/DC converter?

What happens when you take the key out (radio stays on) and you try to open the power window?