My bike is a 750 but here's how I fixed mine:
The power will go to the flasher unit first, then go via a grey wire to your handle bar blinker switch. Via a blue for one side, orange for the other it will split to go to the front, and back blinker, and each blinker will go back to ground via a green wire.
I individually checked each blinker light by plugging the colored wire blue or orange (+) from each blinker directly to the battery, and the green (ground) directly to a known ground.
If the light turns on steady, keep the plus plugged to the battery, plug the green to the corresponding plug. If light stays on, you have a good ground, if it doesn't light up you have a bad ground.
Then test the plus side, connect the grey wire coming to the handlebars directly to the battery, bypassing the flasher, and see if ur blinkers turn on steady.
After all that, if everything turns on, you probably have a bad flasher unit. Anyway, I would replace the flasher for the heck of it, it's less than $4 at your local autoparts, and u r sure it works.