C5/607 rear 12V lighter socket

[dieselnutjob]

I read ages ago that someone couldn't figure out why the rear socket didn't work on their C5. I tried searching for the post but I can't find it.

Yesterday after I think two year ownership I figured out why the rear socket on my 607 sometimes works and sometimes not.
Going throught the circuit diagrams it was clear that the front socket is ignition switched and the rear one is controlled by the BSI.
After ages going through config items in Lexia I couldn't see why it wouldn't power up.

Then yesterday whilst looking at live data I realised that if the rear electric window kill switch is on, the rear 12V socket is off and vice versa. Looked through the owners manual, and under electric windows there it is. If you disable the rear windows then the rear socket is also disabled.

Not sure if the C5 is the same but if so then it might help someone.