Wiper Motor: Description and Operation

Wiper Motor:

The wiper motor is secured with three screws through three rubber grommet-type insulators to a reinforcement with weld nuts on the engine side of the cowl plenum panel. The wiper motor output shaft passes through a hole in the reinforcement into the cowl plenum area, where a nut secures the wiper motor crank arm to the motor output shaft. The two-speed permanent magnet wiper motor features an integral transmission, an internal park switch, and an internal Positive Temperature Coefficient (PTC) circuit breaker.

The wiper motor cannot be adjusted or repaired. If any component of the motor is faulty or damaged, the entire wiper motor unit must be replaced.

The wiper motor operation is controlled by the vehicle operator through battery current inputs received by the wiper motor from the multi-function switch on the steering column. The wiper motor speed is controlled by current flow to either the low speed or the high speed set of brushes. The park switch is a single pole, single throw, momentary switch within the wiper motor that is mechanically actuated by the wiper motor transmission components. The park switch alternately closes the wiper park switch sense circuit to ground or to battery current, depending upon the position of the wipers on the glass. This feature allows the motor to complete its current wipe cycle after the wiper system has been turned Off, and to park the wiper blades in the lowest portion of the wipe pattern. The automatic resetting circuit breaker protects the motor from overloads.