check fuses first (check the underhood and interior fuse boxes for wiper fuses and/or relays).
If they are good, you'll either have to check the rear wiper switch (on the turn signal stack---not so easy) or check for power at the motor when the switch is turned on (requires you to remove the interior panel of the rear hatch).
I would (since i can't find a wiring diagram) check for power at the rear wiper motor.
If not power, then you'll have to checkthe switch.
let me know and I'll keep trying to find a wiring diagram.