Windshield Wiper Motor
An electric motor that drives the mechanical linkage to swing the windshield wiper blades across the glass.
The windshield wiper motor is an electric motor that drives the mechanical linkage system responsible for sweeping the wiper blades across the windshield. Typically located under the cowl panel at the base of the windshield, the wiper motor must operate reliably in all weather conditions to maintain driver visibility during rain, snow, and road spray.
Most wiper motors are direct current (DC) motors paired with a worm gear reduction assembly. The worm gear provides the high torque needed to push heavy snow or resist strong winds against the wiper blades. The motor is connected to a wiper transmission (a series of metal rods and pivots) that converts the rotational motion of the motor shaft into the back-and-forth sweeping motion of the wiper arms. The motor also contains a park switch circuit, which ensures the wipers always return to their rest position at the bottom of the windshield when turned off.
Wiper motors can fail due to electrical issues (such as burnt internal windings or a failed park switch) or mechanical stress (such as trying to operate the wipers when they are frozen to the glass or covered in heavy snow). Symptoms of a failing wiper motor include wipers that move slowly, operate at only one speed, fail to park at the bottom of the screen, make a grinding noise, or refuse to turn on at all.
Replacing a wiper motor requires removing the wiper arms and the plastic cowl cover. Because the motor is linked to the wiper transmission, care must be taken to align the motor arm correctly during installation to prevent the wipers from sweeping off the glass or binding.