if you are using the four input connector, depending on how you connected the, look at the numbers under the grommet. I have 1 and 2 as positive and negative and 3 and 4 as servo in and out. Make sure the female and male ends are the same per number. If you are looking for the wiring diagram for the servo or subs, the subs are in parallel and servo in series. (someone please edit me if I am off).