Principles of Operation (How Does it Work?)

The windshield wiper system uses a two-speed, permanent magnet, three-brush electric wiper motor. When the multifunction switch is in the LO position, the common brush and the blue/orange wire brush are used. When the multifunction switch is in the HI position, the common brush and the white wire brush are used. Current bypasses a portion of the armature winding when the wiper motor is in the high-speed mode. When the multifunction switch is moved to the OFF position, the wiper motor will continue in low-speed mode until the wiper motor reaches the parked position. Then a switch internal to the motor will remove power to the wiper motor.

The interval mode works with the low-speed position of the motor. The interval mode can be set from a 1-second delay up to a 17-second delay. The pause is decreased as the knob is rotated away from the OFF position. It is normal to be able to hear the relay clicking on and off in interval mode.

When the washer system is engaged in interval mode or the windshield wipers are off, the wipers will cycle as long as the washer button is depressed. When the washer button is released, the washer spray will stop and the wipers will stay on for three to four more cycles. If the wipers are in the LO or HI position and the washer button is pressed, the wipers will not change speed or stop. The windshield washer system uses a nonadjustable nozzle jet to spray the washer fluid onto the windshield. The fluid is sprayed in a high-speed continuous stream across the windshield, making a fan-like pattern.

A low windshield washer fluid warning is included on vehicles with an electronic instrument cluster. The LOW WASHER FLUID indicator will illuminate when the washer fluid is approximately one-fourth full or lower. The fluid level is determined by an internal switch to the washer reservoir. If the switch fails, install a new washer fluid reservoir.