Issue with Sony headunit is 99 Dodge Ram

[Primal]

I have a Sony CDX-GT61UI headunit. Here is my problem, It works fine on tuner(radio) and sound comes out of all my speaker system. But when i switch to another input (CD, USB flash drive, Analog input, Ipod) NO SOUND at all. I can skip tracks and the display functions fine, so i know it is reading my media, but no sound. What would cause it to only produce sound on Tuner? I know that it is not the unit itself because i have already returned it to Sony and recieved a replacement with same problem.
Thanks, i just want to hear my own music and not the radio!

[autotoys]

Check your remote wire output, the blue wires on your radio.
Switch them.

[wdricker]

I also have that same sony head unit I'm having the same problem. And I don't have anything hooked up to my blue remote wires because I have no power antenna or a amplifier so I don't understand how switching them would help?

[autotoys]

Usually the blue wire is hooked up turning on any factory amps.
It is hooked up to the POWER ANTENNA blue wire which is on only with the RADIO, when you switch to CD or tape, etc the power antenna lead goes DEAD (since you are not using the power antenna) and your factory amps will not turn on with cd mode.

If you do not have a dedicated AMP remote turn on and your power antenna blue wire goes off in cd mode, hook up the factory amp turn on wire to 12 volt ignition (fused)