DIY aux input

[T.Bird]

I tried posting on e46f about this...and didn't come up with much...but I'll try here as well.

I attempted to make my own aux input cable. I cut down an IDE connector and wired the pins to an 1/8" TRS jack. I could not get "AUX" to show up on the CD player. I heard something about having to wire capacitors in series with the left and right channels with a resistor shunted across them. Tried that, no "aux". Then I figured I didn't have a good connection with the IDE connector...so I soldered the wires directly to the pins on the back of the radio. No "aux". Then I removed the caps/resistor...no "aux".:mad

My radio is business dated 2006...(my car is an '04 though).

I'm thinking there is something wrong with my radio...I'll bet that if I buy the BMW cable it still won't work.

EDIT: I have noticed sometimes though that if the radio doesn't have power for a bit, if I plug it in and cycle modes, aux will show up for a split second...then gone.

[Oli77]

I remember reading that the source has to be on and playing for the mode cycling to pick up the AUX signal.
(I think that is why some people who don't want this do the capacitor trick).
Strange that you have a 2006 radio in a 2004 car.
Can you play MP3 CDs?

[T.Bird]

I tried using it with an iphone, I tried music playing as well with both configurations and no "aux".

I'm not sure about MP3 CDs, I'll give that a try soon.