The later model stock H-D turn signal module (TSM) or the turn signal security module (TSSM) requires a specific amount of amperage draw from the turn signal light bulb to make them flash. Quite commonly, when custom or smaller (or LED) turn signals are installed, they will not provide enough amperage draw to flash the lights, thus requiring the installation of a "Load Equalizer" (often made by Badland). It is a small box (usually installed somewhere under the seat) with one wire attached to the left turn signal wire, one wire connected to the right turn signal wire and one wire routed to ground. The load equalizer creates an extra amperage draw to the system fooling the system into thinking the stock lights are still being used and simply routes the extra amperage safely to ground, allowing the lights to flash. These units because of their design run very hot and usually live a short lifespan of a few years.