Windshield Wiper/Washer System Components
The windshield wiper/washer system consists of the following components:
• | Outside moisture sensor |
• | Windshield wiper/washer switch |
• | Windshield washer fluid pump |
• | Windshield washer fluid level switch |
• | Washer fluid pump relay |
• | RUN/ACCESSORY power 10A fuse |
Windshield Wiper/Washer System Operation
The outside moisture sensor controls wiper motor operation for all low speed
modes. The high speed mode maybe controlled by the both windshield wiper/washer
switch and the outside moisture sensor. The windshield wiper motor is a 2 speed
motor and is operated at low speed in all modes except HIGH. The accessory voltage
supply circuit to the outside moisture sensor provides the power for controlling
the wiper motor. The MIST, LOW, and DELAY modes are controlled by the windshield
wiper/washer switch through a series of internal resistors, and the switch position
determines the point on the resistor assembly where the reference voltage is applied.
For these modes, the windshield wiper switch signal circuit supplies the signal
from the switch assembly to the outside moisture sensor which determines the operating
mode. Windshield wiper motor high speed operation is controlled by the windshield
wiper/washer switch and the outside moisture sensor through the windshield wiper
switch high speed signal circuit. The low speed modes energize the wiper ON/OFF
relay and the voltage is supplied through the wiper HI/LO relay to the windshield
wiper motor. At HIGH position the wiper HI/LO is energized and supplies voltage to
the high speed circuit of the windshield wiper motor.
The windshield washer fluid pump is controlled by the windshield wiper/washer
switch through the windshield washer fluid pump relay. The windshield washer fluid
pump relay coil and switch are supplied battery positive voltage, and during the
windshield window wash modes the windshield wiper/washer switch grounds the washer
fluid pump relay control circuit energizing the relay. During the windshield washer
operation the switch signals the outside moisture sensor also, to provide low speed
wipers operation.
The outside moisture sensor provides automatic operation for low and high speed
when the windshield wiper/washer switch is in DELAY position. The outside moisture
sensor is an electronic module that uses infrared radiation to determine the level
of windshield visibility for the driver, and commands the wiper motor/controller
assembly to drive the wipers to maintain a pre-selected level of visibility.
Windshield Wiper/Washer Signals to the BCM
The BCM receive two signals indicating the operation of windshield wipers and
washer. The windshield wiper switch signal 2 circuit is used by the BCM to
turn ON the headlamps. The windshield washer switch signal is used by BCM to control
the headlamp washers.
Low Washer Fluid Message
The Low Washer Fluid message is controlled by the instrument panel cluster
using an input from the windshield washer fluid level switch. The windshield washer
fluid level signal circuit is supplied ignition voltage through a resistor then
monitored within the instrument cluster. The windshield washer fluid level switch
is normally open so the instrument cluster detects ignition voltage on the windshield
washer fluid level signal circuit whenever the washer fluid level is not low. When
the washer fluid reaches the point where the driver should be informed that the
washer fluid is low, the windshield washer fluid level switch closes. When the windshield
washer fluid level switch is closed the windshield washer fluid level signal circuit
voltage is pulled low, and the instrument panel displays the Low Washer Fluid message
on the driver information center. In order to prevent the Low Washer Fluid message
from being displayed while sloshing is occurring in the washer fluid container, the
instrument cluster is programed with a 1 minute delay before displaying the
Low Washer Fluid message during an ignition cycle.