I have a 2000 Disco II with a Harmon Kardon audio system, it does not have the cd changer. I have been trying to wire in an aux plug with the wiring for the would be cd changer and have been without luck. I need to somehow trick the head unit into thinking there is a cd changer installed, is there any way to do this with the wiring (diagram below) the red, white, black, and gray are for speakers left/right but what about the other wires; Purple, Brown, Green. Is it possible to ground one of these, or give it some low voltage to make it appear that there is a cd changer installed?

Thanks for any help.

 

search around on the net they a people selling cables that just plug in, not need to make anything. start on ebay

 

Why don't you just send the radio off to GB 4x4 Radios and have them install an aux input on the faceplate. I did mine back in March and it works great. Here is their link.
USA | GB 4x4 RADIOS

 

$39.00 here you go Land Range Rover Interface Module Cable iPod iPhone 3 5mm Smart Phone Aux Input | eBay
this plugs in under the passenger seat in place of the CD then just run the cables up between the seat and the console.

 

ISO:
LAND RANGE ROVER INTERFACE MODULE CABLE iPOD iPHONE 3.5MM SMART PHONE AUX INPUT.....can't find them anymore =(