have an old alpine 7982 and want to play

Crap, so there is no way to do this? No way to harwaire it into the 6 disc change plug somehow?

Since the M-Bus changers have just about all quit working because of the age of the laser pickup, I have thrown away my changer controller deck.  I do not need to test anything, but if you can connect it to your radio and it wiorks, we can make it happen. 

Let me know if the changer works. 

I have actually converted an AI Net cd changer cable into an AUX input cable just as you are wanting to do. I simply got a diagram of the plug itsself, found the correct wires you need (left+, right+, & summed-) and soldered them to some female Monster RCA plugs (so I can use my portable DVD player if I so choose), and then I used an RCA to 3.5mm headphone cable (Monster, also ) to use it with Mp3 players or whatever I want. I am still using it for my Mp3 player to this day and it works great.

I did try to use it on an older Alpine deck shortly after I 'made' it, but that particular HU did not have AUX input capabilities so it did not work. I also tried to use it in CD changer mode, but I couldn't get it to work. I do not remember what the model # of that stereo was, but it was a 79-something.

I think you're out of luck...