mp3, rca output

First off, I apologize if this has been discussed, I honestly looked and haven't found anything. I replaced the head unit in my truck with a sony. Playing my mp3 player through the aux jack worked fine with my stock system for several months. I've now installed a sub and replaced the front door speakers which are being run through an amp. Now my mp3 player will not play through the amp. It still plays through the two stock rear speakers. Is there a simple answer for what's going on or have I got a defective unit?

You connected the blue wire of your radio to the remote terminal of your amp.  Disconnect that wire and connect the blue/white wire of the radio to the remote terminal of the amp.

Need model #s of the equipment. also, does the problem only happen with the AUX?

i am an idiot wrote: You connected the blue wire of your radio to the remote terminal of your amp.  Disconnect that wire and connect the blue/white wire of the radio to the remote terminal of the amp.

LOL. I had to walk away from the computer for a sec and didn't see your post. thats where I was going with it if it only happens with the aux

Thanks guys!

Did that fix your problem? 

Yes....My oversight. Never thought to go back and check the wiring since everything else was working fine. Thanks again for your help!