Hi guys! I hope you can help me on this one!

Last night I installed a new Cd changer Sony 565RF for my dad's car (A mystique of course). He went very happy hearing the mp3 files I recorded for him. Today he says me that the cd changer is changing the frequency at wich it transmites and that he has to press the seek button (no big deal). However, i went to his car and founded that i installed the +12V all times to the +12V ignition on the cd changer and viceversa. I installed them correctly and the cd changer wont turn on, so I unhooked the conector out of the changer and I readed the +12V as I should...all the times for yellow and +12V ignition when Ignition BUT when i installed the conector on the changer, I read +6V on the yellow wire all the times and +12V on the red when the key is run; I took the voltage from the wires behind the factory cd unit (can't remeber waht wire I used to conect the yellow wire). Do you think that I have the yellow wire in another wire at the factory cd unit or I have broken the cd changer?