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 to 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 after the wipers are turned off. This is only while the ignition switch is in the "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.

If the ignition switch is turned "OFF" before the wiper is turned "OFF" the arms will not return to a park position. Instead, they will stop instantly.