2003 X5 3.0, how to "turn on" the aux audio input

[khnitz]

Hi all,

I'm installing a handsfree system into a co-worker's 2003 X5 3.0 . It's a non-navigation system with the indash CD player. I have the handsfree audio working correctly (radio mutes and the handsfree audio is played through the vehicle speakers). I also tried to connect an auxilliary audio input for him. From what I've studied in these and other forums, the connections for that are pins 3,4 and 10 (L,R, GND) on the lower-right hand connector in the radio connection block.

What I'm unclear on is, how do you gain access to that audio channel? Does the radio need to be coded to recognize the additional input? I'm guessing that the same "mode" button that selects AM/FM/CD would also go to the Aux port eventually.

Thanks for any help!
Karl in Johnsburg, IL
'89 Volvo 240
'05 VW GTI VR6
'80 BMW 320i (deceased - first car)