Principles of Operation

PRINCIPLES OF OPERATION

The wiper motors receive inputs from the following:
- Multi-function switch
- Ignition switch
- Central junction box (CJB)

The following components are integrated into the wiper motors:
- Windshield wiper motor module
- High/low speed relay
- Run/park relay
- Washer pump relay
- Hall-effect sensor

High Speed Windshield Wipers
High speed is activated when the windshield wiper/washer switch supplies a specific ground input to the windshield wiper motor module. The module then grounds the internal park/run relay and the internal high/low speed relay. Voltage is then sent to the high speed side of the wiper motor, which activates the high-speed mode. High speed mode is exited by selecting a different state on the switch. When the switch is placed in the OFF position, the motor continues to operate until the motor returns to the PARK position and the Hall-effect sensor senses the motor magnet. The output to the run/park relay deactivates the relay and disconnects the voltage to the motor.

Low Speed Windshield Wipers
Low speed is activated when the windshield wiper/washer switch supplies ground inputs to the windshield wiper motor module. The module then supplies ground for the run/park relay, which activates the relay, sending voltage to the low speed side of the motor, activating the low speed mode. Low speed mode is exited by selecting a different state on the switch. When the switch is placed in the OFF position, the motor continues to operate until the motor returns to the PARK position and the Hall-effect sensor senses the motor magnet. The output to the run/park relay deactivates the relay and disconnects the voltage to the motor.

Intermittent Speed Windshield Wipers
The 5 intermittent wiper dwell times are activated with grounds controlled by the multi-function switch inputs to the windshield wiper motor module. When in intermittent mode of operation, the wiper motor operates in low speed. Once the windshield wiper motor module receives the necessary inputs from the multi-function switch, it then activates the windshield wiper run/park relay coil and switches voltage through the windshield wiper high/low relay. The high/low relay remains deactivated, supplying the voltage to the wiper motor low speed input and activates the windshield wiper motor. When the windshield wiper motor module receives the grounded input, the motor continues to operate until the Hall-effect sensor senses the wiper motor magnet, which turns off the run/park sensor output to the windshield wiper run/park software, deactivating the relay and disconnecting voltage to the wiper motor. The windshield wipers remain parked until the windshield wiper motor module completes a time-out and then repeats the intermittent windshield wiper cycle.

Software Safe Mode
The windshield wiper motor defaults to software safe mode when the run/park sensor does not sense the Hall-effect magnet inside the wiper motor. This can be caused by an obstruction of the windshield wipers, a binding linkage, or loss of the Hall sensor signal. The motor continues to operate in a high/low speed condition, and when turned off, the wipers immediately park on the windshield. If necessary, the wipers can be turned on and off until they return to the PARK position.

Washer System
The windshield washer is activated by the internal wiper motor module when it receives a ground from the multi-function switch. Dependent on the correct ground, the internal wiper motor modules activate the windshield washer relay (internal) by grounding the respective relay coil. When the relay is activated, it connects voltage to the washer pump while the washer level switch provides ground to the washer pump.