The original power supply wiring loom is no longer available at BMW. However, since only 5 pins on the 26 pin connector are used, it's easy to make your own cable. For those who want to give it a try, here's the pin layout:
Pin 6: +12v from back up lights(blue/yellow wire at rear light unit),
pin 26: switched +12v (hot on run and start),
pin 14 and pin 18: Ground,
Pin 21: is a switched ground that connects to T4 of Chime module.
The 26 pin connector is easy to disassemble and the pins can be rearranged. It can be obtained at the junkyard. You can find suitable connectors on the instrument cluster and on the body module (Behind the glove box) File away 2 tabs to make it fit in the socket on...