The solder on your wiper circuit board has gone bad, you can ether replace the board ($15.00 Napa, Auto Zone) or you can save your self some money and re-solder the board where the wire harness connects to the board.
Common for this to happen, you can test it by turning your wiper switch on and then tap the wire harness on the wiper board which is a part of the wiper motor assembly.
If the motor stops then it's the board, if not then it's the multi switch on your steering column.
Good luck and keep us posted.
Molson02536