If a turn signal bulb is burnt out, or has a problem with the connection going to the non-flashing bulb, the front light and indicator light on the dash will flash very fast. If it doesn't flash quickly, then the problem is upstream - ie: the Body Control Module.

At least that is my theory.

 

And my train of thought is if that is the case, a battery lobotomy is in order! To reset the BCM and while that neg cable on the battery us disconnected for 20 to 30 minutes, check those ground wires in near the back taillight area

 

at least two years ago, had the "non-canceling" right turn deal......did the fix as illustrated in this forum...............have not had any problems since. this site has fantastic info....thank you.......