[guilty]

If you want to reuse the bulb socket from the grill, only use the 2 outside wires (major [I think] and ground) since the one in the middle is for parking lights which you dont want.

Not sure about resistors, some people say they can run LED bulbs for signals with no problems, some people get burnt-out bulb symptoms. I think you can get LED cluster bulbs with a built in resistor, that would be the easiest way..