alpine no sound on cd

Well I am not master on the audio side of things but I know enough to get by, a few months ago for a friend, I wired up a alpine head unit, (it was a CDA-***) dont remember the model but it was one of the cheaper CD units with the AUX/Ipod hookup in the front. Everything was working fine. He got rid of the car and popped it out and installed it into a 97 Jeep, He was having a problem with it, the audio works fine on AM and FM radio, when you put a CD in it plays the CD but there is no audio from the speakers, the same goes with the Ipod, no audio. I popped the head unit and looked at the wiring, for the most part everything seemed correct, I just need to fix the ground wire, and undo all the twist connections and solder them correctly. I figured it may have been a bad ground but no such luck. I remember a while back I think I had the same issue with another alpine head and it has something to do with the power antenna wire but I do not remember. I am pretty sure it is something easy and not a defective unit.

Please let me know what you think it may be. Any help would be appreciated.

J

you have the power antenna hooked up to your vehicles remote turn on wire!  The remote wire is the blue/white wire coming out of the alpine head.  The power antenna wire is the solid blue one coming out of the alpine and doesn't send voltage if sourced to something other than AM/FM.  switch those two wires and you should be OK.