How to Replace a Buick Century Wiper Motorby Don Bowman
Windshield wiper motors usually fail due to an electrical malfunction, and are relatively easy to replace. However, they are model-specific, so it is advisable to get the production date from the driver's door, directly above the vehicle identification number. Supply the year, production date, make and model to the parts supplier. Question the auto parts salesperson as to whether the specific model year of your car uses nylon snaps. If it does, then you will also need to purchase a new nylon snap and a separation tool.
Open the hood and remove the Phillips screws in the plastic cowl located in front of the windshield. A Phillips screwdriver will facilitate this procedure. Lift the cowl out of the vehicle and set aside.
Detach the windshield washer hose where it passes over the motor.
Detach the wiper gear arm from the windshield wiper motor drive arm. If it is attached by the nylon snap, then insert the tool between the gear arm and the motor drive arm, twist and it will come off. If it does not use the nylon snap, remove the nut securing the wiper drive arm to the wiper and leave the gear arm attached to the drive arm. Pull the drive arm off the motor.
Disconnect the electrical plug on the wiper motor. Remove the three bolts securing the motor to the firewall and remove the motor from the vehicle.
Reverse the procedure to install. The drive arm is slotted so that it will only go on one way. If the drive arm was not removed and it had a nylon snap, then once the motor is installed, simply use the pliers and snap the gear arm on the drive arm.