During Low and Intermittent operation, the windshield wiper washer switch provides a resistor ladder to determine the amount of wiper delay requested. The wiper delay is determined by the BCM based on the input from the wiper washer switch. In the Low and Intermittent position, the windshield wiper washer switch supplies a ground signal to the windshield wiper switch low signal circuit indicating to the BCM that intermittent or low speed wiper operation is request. The resistor ladder determines the voltage signal seen at the BCM, with various voltage levels equaling different delay speeds. Upon this signal, the BCM will apply B+ to the WPR relay coil. The relay coil will become energized, creating a magnetic field and closing the relay switch. B+ will be applied to the windshield wiper motor low control circuit. During low speed operation, the BCM will supply B+ to relay continuously, operating the wipers at a steady low speed. During intermittent operation, the BCM will selectively supply B+, providing the intermittent delay.

In the High position, the windshield wiper washer switch supplies a ground signal to the windshield wiper switch high signal circuit indicating to the BCM that high speed wipers are requested. Upon this signal, the BCM will ground the WPR HI relay coil via the front windshield wiper high signal control circuit. The relay coil will become energized, creating a magnetic field and closing the relay switch. B+ will be applied to the windshield wiper motor high control circuit.

In the Mist position, the windshield wipers make one sweep at low speed and returns to the park position and functions in the same manner as the low speed operation. If the windshield wiper washer switch is held in Mist position, the windshield wipers will continue to operate until the switch is released.

When the wipers are commanded on, B+ is supplied to the windshield wiper motor park switch signal. With B+ applied, the wipers will park when in the at rest state.

During front washer requests, the windshield wiper washer switch supplies a ground signal to the windshield washer switch signal circuit indicating to the BCM that washers are requested. Upon this signal, the BCM will ground the WIPER PCB relay coil and the FRT WASHER PCB relay. This will operate the wipers at a low speed and activate the washer pump for as long as the Wash switch is held.

The windshield washer solvent heater operates along side the standard windshield wiper washer system. When a heated washer cycle is activated, the solvent heater controls the windshield washers through the windshield washer switch signal circuit. The windshield heated washer fluid module is supplied with high current power and ground circuits that are used to energize the heater coils. The low current logic voltage is supplied to the module through the BCM. The heated washer cycle operation is activated by a separate switch located on the headlamp switch. When the heated washer fluid switch is pressed, the heated wash switch signal circuit is momentarily grounded and the heated washer cycle is activated. During the heated wash cycle the 3 heater elements in the solvent heater are energized, and when the solvent temperature reaches approximately 70° C (160° F) the heater grounds the washer switch signal circuit until the heated solvent is dispensed. The heated washer cycle will run 4 heat and wash actions unless deactivated by the heated washer switch.