[Craw2theJ]

Originally Posted by M_Bimmer

Your 12VDC electrical sockets, are powered off of the Terminal 30B power rail, and is relayed controlled by the BDC.

Terminal 30B provides the voltage supply for control units and components that in normal operation are required when the driver is present. For example, terminal 30B will be activated with a status change for a door contact or unlocking, locking or securing the vehicle.

The Body Domain Controller (BDC) is the master control unit for the terminal control. The LIN power distribution box is implemented with an intelligent actuation of different relays and terminals for the rear and front power distribution box. The LIN power distribution box is installed in the rear power distribution box as pluggable separate component.

The BDC control unit activated the LIN power distribution box through the LIN bus. The LIN power distribution box switches on the terminal 30B relay. Terminal 30B is connected with the excitation coil. Terminal 30B relay is applied. This switches terminal 30 to the terminal 30B power distribution box in the front left power distribution box.

The status of the relay is returned to the BDC control unit via LIN bus.

THE FOLLOWING IS NOT RECOMMENDED, but will answer your question.

The trunk socket, X98, is shared with sockets X104 and X105, on Fuse F273.

Your ONLY option would be to follow the red wire on socket X98 over to the wire junction in the trunk (shown below), and remove the wire from the wire bundle node, X1434. Then take the X98 red wire, and connect it directly to the positive terminal on the battery in the trunk.

Thank you for the response and amazing explanation. Do you happen to know if any of the 12 volt outlets have constant power? I had an e38 and the front outlet for the cigarette lighter always had power....which I know is much older technology than the g12.