Not sure what bike you have, but I had the same happen to my 71, just bought a replace blinker relay from honda and it started working again...the relay on mine was bad. I would replace the bulb and try, it, if that doesn't work then look at the voltage you're getting at the bulb and backtrack the wires if you have issue there. When my relay was going...it would click and flash sometimes, then just once then not flash at all. Wiring diagrams are on this site...if you haven't foudn them already. Good luck!