Wiper and Washer Systems: Description and Operation

WIPERS AND WASHERS

The windshield wiper motor known as the smart wiper motor has its module integrated within itself. The internal components of the wiper motor module are the high/low relay, washer pump relay, and the run/park sensor.

The windshield wiper motor receives its inputs from the multifunction switch. These signals are ground reference signals. When the multifunction switch is placed in different positions, various input signals are selected and sent through circuits to the wiper motor. The wiper motor module identifies these selected input signals and activates the wiper motor to the selected function.

High Speed Windshield Wipers
High speed is activated when the multifunction switch supplies a ground to the windshield wiper motor module inputs and the internal hi/lo speed relay. The module then supplies ground for the run/park relay, which activates the relay, sending voltage to the high speed side of the wiper motor activating the high-speed mode. At the end of each cycle, the park sense determines the state of internal run/park relays for voltage or ground. Depending on the state of the relays whether or not the wiper motor module needs to request another cycle.

Low Speed Windshield Wipers
Low speed is activated when the multifunction switch supplies a ground to the windshield wiper motor module inputs and the internal hi/lo speed relay remains in the same state. The module then supplies ground for the run/park relay, which activates the relay, sending voltage to the low speed side of the wiper motor activating the low speed mode. At the end of each cycle, the park sense determines the state of internal run/park relays for voltage or ground. Depending on the state of the relays, the wiper motor module might request another cycle.

Intermittent Wiper Speed Windshield Wipers
The intermittent wiper speeds are activated with grounds. They are controlled by the multifunction switch inputs to the windshield wiper motor module. The module then activates the windshield wiper run/park relay coil and switches voltage through the windshield wiper high/low relay. The relay remains deactivated, supplying the voltage to the wiper motor low speed input and activates the windshield wiper motor. When the module receives the grounded input, the motor continues to operate until the Hall-effect sensor senses the motor magnet. The run/park sensor will be turned off, and the output to the run/park software will deactivate the relay and disconnect the voltage to the motor. The wipers remain parked until the module completes a time-out and then repeats the intermittent wiper cycle.

Default Mode
The windshield wiper motor defaults to this mode when the run/park sensor does not sense Hall-effect magnet inside the wiper motor. This can be caused by obstruction of the windshield wipers or binding linkage. The windshield wiper motor will continue to operate in a high/low speed condition for a period of 60 seconds.

Washer System
The windshield washer is activated by the windshield wiper motor module when it receives a ground signal from the multifunction switch between the washer input. Depending on the correct ground, the internal wiper motor module activates the windshield washer relay (internal) by grounding the respective relay coil. When the relay is activated, it connects voltage to the washer pump.

Low Washer Fluid Level Lamp/Indicator
The low washer fluid lamp/indicator feature is controlled by the FEM and the instrument cluster. The low washer fluid switch is hardwired to the FEM. If the fluid level is low, the FEM will send a message via the standard corporate protocol (SCP) communication network to the instrument cluster. The instrument cluster will then process the message and output an audible and visual warning.

The stay pad is attached to the bows and is repaired as a component. The number two bow is spring-loaded. Only one new stay pad at a time should be installed.

The convertible top hydraulic system is comprised of the lift cylinders, the motor, the connecting hydraulic lines and a convertible top switch. The hydraulic system, except for the convertible top switch, is removed as an assembly, but the components may be repaired separately.

With the transmission in PARK, the powertrain control module (PCM) determines the PARK position from the digital transmission range (TR) sensor input. The PCM sends a message over the standard corporate protocol (SCP) communication link to the front electronic module (FEM). The FEM then allows operation of the convertible top.

The convertible top switch supplies a ground signal to the FEM. The FEM sends the signal to the rear electronics module (REM). The REM grounds the appropriate relay to raise or lower the convertible top. When the raise or lower relay is operating, the other relay remains in its normal state supplying the motor/pump ground.