Use the link to the manuals that papaindigo gave you.
Go to the wiring section, Wipers, pages 8W-53-4/5
Circuit breaker number 3 is on the reverse of the Junction Block ie. the internal fuse panel. This is for anything jamming the wiper motor or blades or a burnt-out motor.
The wiring diagram will show the breaker's location...it may need re-setting.
The wiring diagram will also show where relays "Wipers On/Off" and "Wipers High/Low" are located on the rear of the Junction Block...swap these with identical relays nearby.
Then check the ground point, G111, is good. Using the Wiring Diagram there is a section called "Locations"....this shows you where the Ground points, Connectors, Splices etc. are located. You can temporaly splice a piece of wire into the Black wire at the motor and connect it to a clean chassis point to get an extra ground.
You will need to trace the wiring all the way from the BCM, Multi-function Switch to the motor or the other way round...after 34 years in the computer/robotics industry I can assure you whichever route you take will be the longest one!
You may find a dirty pin in one of the connectors on route...best way to test for voltage is to have the negative lead of the DC meter on chassis and strap a small sewing needle or pin to the Red positive meter lead...piece the insulation of the wires with this needle to check for voltage...the small holes in the insulation can be filled with glue later.
Have fun!
