Audio Systems: Ford F 150 cd changer and radio, ford f 150, lincoln radio

Question
I have a 2000 Ford F 150 lariat.  It's Factory radio has a 6 disk CD Changer.  The Radio works fine but in order to go from FM to CD you have to turn the truck off and put the key in accesory position and change it.  Also if you turn the lights on (the radio lights dim) the radio will switch stations and you can't control it.  It seems to be a short when the head lights are on.  Is there a wire that I can check or even disconnect that will solve this?
Thank You in Advance

Answer
i believe the radio is bad there is no cable or have nothing to do with the lights  i seen this radios go crazy lock stay in one station the  lights going very dark radio needs to be service or replace  


http://www.oemautosound.com/pc-178-120-ford-lincoln-radio-f8vf-18c870-ag.aspx