I currently have an Alpine CDM-7857 HU and I am trying to take advantage of the CD Shuttle MBus input (round 8 pin) to input from my MP3 player. I purchased a cable from ebay


which states it will do the job and has the 1/8" stereo plug to go into the MP3 player but I can't get the AUX function to come on, it just toggles between the radio and CD. Nothing in the manual about adding the CD shuttle setting. I have also tried resetting the unit with the little red button behind the faceplate.

Any ideas? will this cord work?