steering wheel interface

hi guys i'm hoping someone has done a 1997 bmw 528 steering wheel interface(swi-jack p.a.c)and could advise on a problem i'm having,according to instruction that came with the module the wire for the interface is at the steering column but the problem is ur're suppose to find the color for the wire behind the radio then go to the steering,i got the wire at the radio but there's no such color at the steering.....i end up using the wire at radio to program the module and it work but it doesn't work properly sometimes it send the volume up without even touching,sometime it don't even respond,any advise appreciate....oh i called pac tech support and they can't help me,the radio i'm using is kenwood kvt-512

well this is how i have hooked them up in the past ive never used the wire behind  the stereo. but try this, You must get the wire at the steering wheel column. Cut wire in half. Connect the INTERFACE's Yellow wire to the steering wheel side of the cut wire. Insulate remaining cut wire. The "R/T" button is NOT programmable and you should wait 15 seconds after key is turned on to start the button programming. hope that helps