Principles of Operation

PRINCIPLES OF OPERATION

The windshield wiper motor is a smart wiper motor with an integrated electronics module. The internal components of the motor are the high/low relay, washer pump relay, and the run/park relay and associated electronics.

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

High Speed Windshield Wipers
High speed is activated when the windshield wiper/washer switch supplies a ground to the windshield wiper motor internal park/run relay and the internal HI/LO speed relay, through circuit 63 (RD). 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 a ground to the windshield wiper motor inputs through circuits 56 (DB/OG) and 61 (YE/RD). 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 Wiper Speed Windshield Wipers
The intermittent wiper speeds are activated with grounds. They are controlled by the windshield wiper/washer switch inputs through circuits 56 (DB/OG), 58 (WH), and 61 (YE/RD) to the windshield wiper motor. The module activates the run/park relay coil. The high/low relay remains deactivated, supplying the voltage to the motor low speed input and activating 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, and the motor returns to the park position. The output to the run/park relay deactivates the relay and disconnects the voltage to the motor. The wipers remain parked until the module completes a time-out and then repeats the intermittent 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 windshield wiper motor when it receives a ground signal from the windshield wiper/washer switch washer input through circuit 680 (LB/OG). When a ground input is received on the wash request circuit, the internal module activates the internal windshield washer relay by grounding the respective relay coil. When the relay is activated, it supplies voltage to the washer pump. When the internal module activates the internal windshield relay, it also activates the internal run/park relay to operate the wiper motor.