I have an 09 f150 xlt with sync but have a problem. I installed an amp to power my door speakers but when I hooked into the positive and negative of the speaker leads out of the head unit to install the LOC (line out converter). The say a command button doesnt make the girls voice on to the speakers just on the display. As soon as I hooked everything back to stock again she would come on the speakers again. What am I doing wrong?