The most likely problem is the turn signal flasher relay. A $10.00 part usually. I am attaching images to detail where the flasher is. All you have to do is unplug it and plug in the new one, and it should be good to go.
If that does not do it, then we are probably looking at a bad multi-function switch (aka the turn signal switch), which is more expensive and more complex to replace.
Change the flasher and let us know what happens. We will go from there.
Images (Click to enlarge)
Wednesday, October 3rd, 2018 AT 5:14 AM