2004 Daytona 955i, 2018 Indian Roadmaster, 2014 Triumph Scrambler, 1980 CB650C in resto
The fast blinking is a design feature. If one of your blinkers isn't working, the blink rate will double. As for why it's not working, try putting the old one back on and see if it works. If not, the wiring harness may be the problem. If it does, put the new one back on and see if it works this time. If not, the new one has a problem.