turn tail light drivers side will not turn off

It is a turn signal light. It will not go off but it still blinks when told to turn left as does the right side. did what you suggested and stays on still.

Try replacing the flasher unit under the dash first. It is cheaper and easier to do first just to see if it is the multifunction switch in the column

Unplugged the after-market trailer hitch wiring harness. Problem solved. Guess I need to replace it

Where is the wiring harness for trailer