I recently purchased an aftermarket Alpine stereo and installed it myself. It works great except for one thing... there were RCA inputs in the back so I purchased an RCA coord for my iPhone and ran the cable through the back and out into the glove box. I was not smart enough to test it before I put the dash and everything all back together again. When I hook my iPhone up to it the volume bar disappears so the iPhone obviously detects that it's hooked up to something but it will not play. Anyone have any ideas what's wrong.