Head Unit...
Dude, honestly it sounds like your Wire Harness is messed up. I understand the thrill of making something, but for like 15 bucks you coulda bought one at best buy and it wouldn've worked fine. Your Head unit should work independently of the CD changer. The CD changer just plugs into the IP Bus on the Back of the radio. So chances are pretty good that if you're having power problems this is why. The pioneer is great head unit. I take it you have the one with the AUX in? I just picked up Sirius, (GO Howard), and have it hooked in thru the aux in. The cable was 30 bucks at B-buy. It also works great for hookin up an ipod as well or any other portable media device.
Randon
99 Ebony Black
The Jersey Fish
East Rockaway NY
NYPD's Finest