Turn Signal Flasher For LED Lights 3-Pin. We occasionally have a question about slow or erratic flashers when changing over to the super fast LED lighting. Here is the solution. You absolutely must use this flasher if you have changed both tail and park lights to LED! This is a direct replacement for the common 3 pin flasher used since in the early models. Just plug it in and hook up the ground wire. Lasts 10 times longer than a regular flasher.