LED lights and flasher issue

I've just got my new taillight assembly wired in, testing the wiring (ran new cable from the battery box as the old cable was not much good. I've discovered everything works, except the indicator flasher is not seeing enough load from the new LED lights to blink. I'm after suggestions: should I just add in a load balancer and leave the front indicators, or replace the front indicators as well and put in an LED compatible flasher?