I noticed the flasher relay going nuts (clicking more quickly than ususal) on my '12 for left turns this weekend. I pulled the bulb out and couldn't see any problem. However, I put in a new bulb and the problem was solved. Bulb filaments can be severed without a visible break in the wire. Bulbs are cheap and easy. Try replacing the bulb and see if that solves the problem.
For me, I knew that the flasher still worked since I could hear it and the right side worked fine. I also knew that front left turn signal worked as I could see it reflecting off the bumper of a car in front of me at a stop light. It wasn't a fuse as all those functions are on the same one and some worked. So that left the bulb or the wiring. Start with the obvious - bulbs burn out - and then work up the food chain.