How Does the Wiper Motor Work?
When the motor is activated, power is generated and sent through the worm gear mechanism to increase the amount of torque and reduce the speed of motion. If it weren’t for this gear, the mechanism would not have enough strength to activate the wiper from a stop, while the speed of rotation would be too fast. When the speed is varied, different terminals reconnect within the motor so that current flows through high or low speed brushes internally. When everything is switched off, power is diverted to a special “parking switch” until the gear rotates to a point where it operates a parking switch plunger, killing the power when the blades have rotated back towards the bottom of the windshield.