Wiper and Washer Systems: Description and Operation

There are four different operating modes of the wiper system: off mode, low speed mode, high speed mode and interval mode.

In the off mode, there is no windshield wiper motor activity and the windshield wiper motor will be in the PARK position.

In the low speed mode, the windshield wiper motor will be set to a low speed setting. The windshield wiper hi/lo relay is deactivated, while the windshield wiper run/park relay is activated.

In the high speed mode, the windshield wiper motor will be set to a high speed setting. The windshield wiper hi/lo relay and the windshield wiper run/park relay are both activated.

In the interval mode, the windshield wiper motor will be set to a low speed setting with the windshield wiper hi/lo relay deactivated. The windshield wiper run/park relay is activated at the beginning of each wipe and deactivated when the windshield wiper motor park switch reaches the RUN position.






The permanent magnet three-brush F windshield wiper motor allows selection of either low or high speed, when selected via the steering column mounted multi-function switch When the multi-function switch is in the LOW position, the common brush and low speed brush are used. When the multi-function switch is in the HIGH position, current bypasses part of the armature winding to the high speed brush. When the multi-function switch is moved to the OFF position, the windshield wiper motor will continue to run at low speed until the windshield wipers park.

When the multi-function switch is in the Interval (INT) position, the windshield wipers will make a single sweep followed by a pause. The control knob on the end of the multi-function switch adjusts the pause from approximately 1-20 seconds.






Vehicles equipped with a Generic Electronic Module (GEM) are available with the speed-dependent interval wiper feature. During the interval mode, the delay between successive wipes will decrease with higher vehicle speed to compensate for increased water on the windshield glass. This feature will relieve the operator of constantly switching between interval settings. This feature may be enabled or disabled with New Generation STAR (NGS) Tester active command SPEED DEPENDENT WIPER.






To engage the windshield washer, push the knob of the multi-function switch toward the steering column. When the multi-function switch is in the OFF or INT position, the windshield wipers will run at low speed as long as the knob is depressed. When the knob is released, the washer will stop immediately. but the windshield wipers will continue to run for two to three sweeps, then return to their previous set operation. Washer engagement does not affect windshield wiper operation when the multi-function switch is at the LOW or HIGH position.

Feature inputs:
^ Ignition switch RUN position: (battery potential on both RUN and RUN/ACC inputs).
^ Ignition switch ACC position: (battery potential on RUN/ACC input only).






^ Wiper switch position: (different resistance for each mode; see Wiper Switch Resistance Values table).






^ Interval Delay/Wash switch position: (different resistance for each mode; see Interval Delay/Wash Switch Resistance Values table).
^ Windshield wiper motor park switch: (ground for PARK position and battery potential for RUN position).
^ Vehicle Speed Sensor (VSS) sensor (sinusoid wave. 0.7V - 20V, 2.2HZ/MPH) (GEM only).

Feature outputs:
^ Windshield wiper hi/lo relay control (ground to activate and open circuit to deactivate).
^ Windshield wiper run/park relay control (ground to activate and open circuit to deactivate).
^ Washer pump relay control (ground to activate and open circuit to deactivate).