I believe I have found a feasible way to connect any outside source via the CD changer input but I need help!

I picked up the following part:

Part #MR495781

It is the stock HU to optional changer cable. Cost about $45 at the Mitsu dealer.

So the pins on the HU end should be in the right place, however I don't know what each pin is assigned to. Is there anyone who has a schematic of the CD changer input on the stock HU? Ideally, I'd like to know the use of every pin, however most importantly are left, right and power.

I have a cable from a car charger/cassette adapter that I modified on my last vehicle. I'll be combining this cable with the one I just purchased.

Thanks!