You never really said why you changed the head unit in the first place. But here we go. Bose speakers do have a weird impedance but as long as the amps are in place it shouldn't matter. Now you could use the harness that allow you to use your rca outputs for signal. Or you can bypass the amps at their respective locations. Which is always the best way to go. In any case most HU have 2 remote outs one is for the antenna and the other is for the amplifier. Make sure they are connected to the correct wire. Also make sure they are powering up and staying powered up threw all functions.