The rear wiper motor in a Chevy Trailblazer should last the life of the vehicle since the rear wiper tends to be used less frequently than the front wipers. However, there is no guarantee that the rear wiper motor won't fail due to an electrical short or premature motor burnout. When this happens in your Trailblazer, you need to replace the rear wiper motor.
Pull the rear wiper arm away from the rear window until the arm locks into a position that is perpendicular to the rear window.
Remove the small retaining nut at the base of the wiper arm with a socket wrench.
Pull the wiper arm off the wiper motor.
Open the rear hatch area and remove the screws holding the trim cover in place (it covers the wiper motor).
Remove the trim cover. You may need to pry it off with a flat tip screwdriver.
Disconnect the electrical connector running to the wiper motor.
Remove the two bolts holding the wiper motor in place and pull the motor off the rear hatch frame.
Install the new motor, reassembling the system by following the above steps in the reverse order.
