Way to vague of a question. Could be just a wiper blade that is simple or a motor which is difficult. Hopefully just the blade broke...see sources and related links below for wiper blade information.
because it's broken
2003 GMC Envoy rear wiper troubleshooting - check in this order: Fuse, switch, spindle/tightness of arm, motor, wiring. See the Sources and Related Links section below for rear wiper blade information.
Remove the rear wiper arm from the wiper motor. Remove the wiring harness from the wiper motor. Remove the wiper motor retaining bolts. Reverse the process to install the new wiper motor.
To shut off the rear wiper on a 2003 GMC Envoy XL, locate the rear wiper control switch on the turn signal stalk or the dashboard. Turn the switch to the "Off" position, or if it has multiple settings, cycle through the options until the wiper stops. If the wiper continues to operate, check for a malfunction in the wiper motor or the switch itself.
If the rear wiper on a 2001 Isuzu Rodeo will not turn off it could mean that the rear wiper switch is broken. The cost to replace the switch averages around $200 if done by a professional mechanic.
rear wiper, rear defrost
Check the fuse. If the rear wiper fuse is good then it could be a wiring problem. Check the wires to the rear hatch, then check the motor itself.
Resubmit question describing the problem. Question too broad. What is it doing? What is it not doing? Wiper arm? Wiper blade?
Rear Wiper Motor R&R Remove the rear pivot arm. Lift the pivot arm to the upright position. Slide the locking tab out. Pull up and remove the pivot arm. Remove the rear wiper motor shaft nut cover. Remove the rear wiper motor shaft nut. Remove the rear wiper motor cover. Remove the rear wiper motor bracket nut. Remove the bolt and the rear wiper motor. Reverse these steps to install.
Rear Wiper Motor R&R Remove the rear pivot arm. Lift the pivot arm to the upright position. Slide the locking tab out. Pull up and remove the pivot arm. Remove the rear wiper motor shaft nut cover. Remove the rear wiper motor shaft nut. Remove the rear wiper motor cover. Remove the rear wiper motor bracket nut. Remove the bolt and the rear wiper motor. Reverse these steps to install.
On a 2003 Lincoln Navigator : To turn on your rear windshield wiper , on your turn signal lever closer to the steering wheel is : - INT 2 - INT 1 - OFF
Yes, if it is worn and not working efficiently.