Turn signal Puzzle

I have started bringing my car out of mothballs and encountered a puzzling turn signal issue. The left turn signal works inside and out the right turn signal lights the dash light and both front and rear external lights, but no flash. The emergency flasher flashes all four corners and the dash indicator lights. I know the two functions have their own flashers but the turn signal flasher doesn't know left from right according to my wiring diagram. Ideas?
Author: joekamm