rear wiper wiring issues

My rear wiper hasn't been working, so I changed the rear motor and still had no luck. i then changed the circuit board for the motor and this still didn't work. I have power directly from the switch to the circuit board on one wire, is this right? Is there any troubleshooting anyone can advise me to do or is there a common problem I should know about? Does anyone havea wiring diagram i could reference? Its a 96 Jimmy.