[38bill]

Pretty sure that typically the old brake switch wire is abandoned as all it does is light both rear brakes lights. The power for the brakes and flashers now goes through the new turn switch and flasher unit and you need a brake light wire for each side. You could separate the brake lights and use the existing brake light wire for one side and run a new wire to the other side but I like to start will all new wiring. You would probably have to extend the existing wire to reach the new signal wires anyway.