I tried this also. You need a resistor to make the light dim when the blinker is on. The resistor makes it seem like there is a regular bulb in there. I had a smitload of resistors and tried a bunch but wasn't satisfied with the way it works. You also need an LED flasher relay too to slow the blinker down.They're cheap on eBay. Just google something like 3 to 2 or 2 to 3 led signal lights and you'll find something.