Wiper and Washer Systems: Description and Operation

Windshield wiper operation is controlled by a dash or column mounted switch. Wiper motors have permanent magnet fields, and high and low speeds are determined by current flow through the appropriate set of brushes. Delay operation on intermittent systems is controlled by a variable resistor in the wiper switch, a dwell switch in the wiper motor and a control unit/relay assembly.
Wiper arms on both systems return to a park position when the system is switched off with ignition in ON position. Standard two-speed systems complete the wipe cycle and stop in park position, while intermittent systems complete a full wipe cycle before parking.