Hello everyone im new to the forums...im 16 and i own a 1998 lincoln town car signature series....it has the "jbl premium sound" and i installed a kenwood kdc-mp238 deck.....if i plug in the ap part of the wiring harness i get sound from sub and small sound from speakers....if i dont plug in amp part of harness i get small sound from speakers...no sub....how do i get this wired up so it will all work together like with stock radio?