I recently installed LED flashers in my Firepower and had to remove the big warming resistor (as Vid said) or else the flashers would stay on all the time. Upgrade the 2 side lights to LEDs in the FIRE and POWER inserts at the same time if you haven't already. It really brightens up the inserts. Only problem is you will end up puting LEDs under all the inserts once you see the bright colors.