I have a 1991 Jeep Wrangler Renegade, the turn signal/wiper arm with the flat lever on top, that pushed forward and backward doesn’t cycle the wiper or mists the window. You can twist the knob on the end of the wiper lever and all wiper functions work. I hot wired the washer motor and it works and squirts water out the nozzels. What causes this??? Thanks. 
