You'll have better luck with pics. Here are the connectors I have:


The connection on the left is the bigger of the 2 plugs. It contains:
Black: Right + Signal
Yellow: Left + Signal
Brown: Common - Signal
Purplish: IBus

The smaller plug on the right is the power.
Red: 12V+
Brown: Ground
White: 12V Switched

The connections from the left plug go the wire harness on your BM54. I have a BM53 that looks like this:


In the bottom right of the picture you can see the other end of the signal wires from the CD Changer - black, brown, and yellow.

Ibus needs to be spliced into an IBus connection as well.

d-