Okay. I have been struggling with this problem a while. My fj's left indicators wont work, the blinker relay just flashes rapidly, bulbs are ok.
Problem started by right indicators doing the same thing, problem just chanced side :) Relay sounds like one bulb have failed but they are intact.
Bike is -90 fj 1200
I ran into the same problem several months ago with my left front turn signal light. Swapped out the bulb only to find out that wasn't the problem. Turns out the wire to the turn signal had been pinched/cut under headlight by the front forks against the frame. I guess that must have happened while pushing the bike around the garage.
In my case neither front or back indicators work. Tried to read those electric diagrams but did not understand them enough.
(Quite well for professional electrician..)