I just tried this and If u have the fader intact, you can just use the wires into the radio. Cut the connectors there split the 2 wires the black connector is the left side, the white is right. You will have 4 wires, 1 each for + and - for left and right coming from the dash now. Splice the + & - together from your deck (e.g. rear right and front right) and connect the corresponding side to the wires coming out the dash. What you should have when u are done are a pair of wires from the deck to each wire in the dash. this will give you fader control in the center still.