My sister's car had this problem from the time she bought it (with about 70K miles on it) and we accidently fixed it-not sure if it was a fluke or if this will work but I thought I'd share what happened.
We initially figured it was just some sort of short because the blinker would only work about 1/100 times. We took out the harness that the blinker bulb fits in (yes, it comes completely out of the car, it is not attached to wiring holding it in) from both the driver's side and passenger sides of the car. My intent was to switch sides (put the driver's harness on the passenger side, and vice versa) to see if the problem was the harness or if it was some deeper wiring problem on the passenger side.
Essentially, once I put the harness from the passenger side to the driver's side and vice versa, both sides began working perfectly every single time. I do not understand why but I won't question it either.
Let me know if you need more detail and I wish you the same weird luck we had with ours!
Sunday, October 21st, 2018 AT 5:16 PM