Yes, in minnesota we call them blinkers, not turn signals. LOL. Anyways, my left turn signal is slower than the right. And, when I'm driving with the headlights on, it is one "blink" every 5 seconds or none at all. The right side is fine? Dont understand man.
I went to Elkhart Lake to the vintage road races once. It was beautiful, It looked a little like the Central Valley in CA only greener. But I kept seeing signs for snowmobile crossings! For a guy from CA it was unimagineable!
When I went thru the gate and the cheerful ticket taker exclaimed "nice car". I didn't have the heart to tell her it was a standard issue rental car from the airport, dk grey olds, I think. It just struck me funny.
The older I get, the faster I was!
This is a ground problem, no doubt about it. However, spend the $4 and get a new flasher relay to be sure. I had this happen when the inside of the lamp socket gets all corroded and cruddy. ALso possible to have a corroded Fisher Connector (wiring). Good Luck