The short answer is maybe. Put your ignition switch in start with no wires hooked to starter and see if you get 12 volts on that 10 ga wire you ran. If so, you don't need it. If not, you do. It gets hooked up to the S terminal on the solenoid, which usually has a purple wire going to it. I think it is typically the one closest to the block. Originally the pink wire ran from the the "S" post on the solenoid to the coil to give a full 12 volts to the coil during startup to help the engine fire off better back in the points days.
