I believe there are three different OBC's. A seven, and eleven, and an eighteen button one. Also I believe each has it's own wiring, especially the big one. So the short answer, I'm not sure. Check to see if there is any extra wiring in the dash outlet when you pull the clock.
1995 325I, window tint, K&N, debaffled airbox, BMW #104 wheels, Nighthawk low beams, smoked side markers, smoked corners, smoked taillights, M3 stlye heated mirrors, various interior bits, Bosal cat-back.