Markissbolo

Recently taken interest in installing a amp in my legacy. This car had a factory amp under the drivers seat which blew due to the headunit having its own amp in it. I’ve redirected all of the speaker wire into the plug that would normally plug into the amp so the speakers can keep going. I have an external amp in the trunk than it all hooked up with power rca etc but it still won’t work. Do I need to attach it to something under the drivers seat? I’m stumped any help is welcome