Windshield Wipers

There are three types of motors that can be used for windshield wipers. The permanent "magnet" motor has two ceramic magnets that are cemented to the field frame and does not use field windings. It needs less energy than the other types of motor design, but the switch must be wired in series, creating many areas of resistance. The "shunt wound" motor provides a very consistent speed, but doesn't provide much torque upon starting. The "compound" motor wiper has a strong starting torque and provides consistent speed, but it is the most expensive. Most cars have an intermittent wiper system, which permits the driver to select a delayed wipe that operates only every few seconds. A representative wiper/washer unit is the wiper assembly, which incorporates a depressed park system that places the wiper blades below the hood line in the parked position. The relay control uses a relay coil, relay armature, and switch assembly. It controls starting and stopping of the wiper through a latching mechanism. An electric washer pump is mounted on the gear box section of the wiper. It is driven by the wiper unit gear assembly.