Here's something to test out.
Unplug the connector that plugs into the wiper motor. Turn the wipers on (with the wiper motor unplugged) and use a test light to see if any of the connections to that plug are getting power (the test light will light up if they are). If they aren't that means you're not getting power to the wiper motor and that it's something else.
Have you checked to see if there's a wiper / sprayer relay? You could have a bad relay.