A: Your new turn signal housings should have 3 wires, if they are to support a dual filament bulb. One wire will be ground (usually black or green), then; two more wires. One for each filament. The brighter filament needs to be used for turn signal. The other (in this instance), for running lights. You should work with long lengths of wire from the new signal housings and make your connections under the seat into the stock taillight plug. On a 1994 Harley (taillight plug), the black wires are ground – purple are left turn signal – brown is right turn signal – blue & orange are constant 12V power. You will want to power your running lights from a blue or orange.
Turn Signal Brake Light Module Conversion Kit