The wiper motor on your Chevrolet Express may burn out over time with regular use. Replacement motors can be purchased from the Chevy division of General Motors. Even if your wiper motor hasn't failed, you should check it periodically as a precaution. When your Express' motor starts to squeal or strain, you should replace it before it completely dies. The first step, however, is to remove the motor located on the firewall inside the engine bay.
Open the hood of your Chevy Express and remove the electrical power connector running to the wiper motor.
Remove the two bolts holding the wiper motor to the firewall.
Pull the wiper motor off the pivot arm assembly and remove it from the engine bay.
