There is not enough amperage draw on an LED light to activate a normal flasher unit. Ron Francis sells a special flasher unit that you will require to make it work. If you want to cheat and use an ordinary flasher you could probably run a parallel circuit to a hidden 1157A bulb which would draw enough load to activate a normal flasher unit. You would need one paralell circuit for each side of the car, but that seems like a lot of effort to get around using the proper flasher unit.