possibly the relay located on passenger side. But make sure the bulbs are seated properly, no corrosion. The rear bulbs are dual filament one may be outYesterday, my left-hand blinker went into overdrive. Blinking at least twice as fast as it should.
Here's what I know that might be relevant:
All bulbs work.
Every once in a while the turn signal lever hangs up when turning it on for a left hand turn. Actually hasn't been doing it lately.
Had new flasher put in a few weeks ago. Emergencies had been coming on by themselves. Will also put in rebuilt climate control display next week.
Immediately before the problem started, I had a paintless dent removal guy here working on the car (really interesting and effective BTW). While working on the opposite corner (right side), he removed the blinker light module to make a repair. To my knowledge, he didn't take out the left side module.
PS: The car is really coming along. Will post pics when I'm finished. I love the car, but I must admit that I am a bit frightened of the electrical system.