Principles of Operation

PRINCIPLES OF OPERATION

Windshield Wipers and Washers
The windshield wiper system consists of an integrated wiper motor and module assembly, which contains internal washer, run/park and high/low speed relays. The windshield wiper motor and module assembly also contains a Hall-effect sensor that is used to determine the parked position of the wiper motor during a cycle. The integrated windshield wiper motor and module assembly has 5 different operating modes: OFF, LOW speed, HIGH speed, INTERMITTENT and SOFTWARE SAFE mode.

High Speed Windshield Wipers
When the wiper switch is set to the HIGH speed position, it supplies ground to the high/low speed relay coil and the high speed inputs of the internal windshield wiper module, which causes the windshield wiper motor to cycle at high speed. During high speed operation, the internal run/park and high/low relays are both activated, and supply 12 volts to the internal low and high speed inputs of the windshield wiper motor. The high/low speed relay coil ground is hard-wired to and controlled by the wiper switch, while the run/park relay coil ground is controlled by the internal windshield wiper module based on inputs received from the wiper switch. Since the high/low relay is controlled by the position of the wiper switch, the windshield wipers will still operate in high speed mode if the internal windshield wiper module fails, but will not automatically park when the wiper switch is turned to the OFF position.

Low Speed Windshield Wipers
When the wiper switch is set to the LOW speed position, it supplies ground to the internal windshield wiper motor module low speed inputs, and the windshield wiper motor cycles at low speed. During low speed operation, the internal run/park relay is activated and supplies 12 volts to the low speed input of the windshield wiper motor. The run/park relay coil ground is controlled by the internal windshield wiper motor module based on inputs received from the wiper switch. Since the run/park relay is controlled by the internal windshield wiper motor module, the wipers will only operate in HIGH speed mode if the internal windshield wiper motor module fails, and will not automatically park when the wiper switch is turned to the OFF position.

Intermittent Windshield Wipers
When the wiper switch is set to one of the 5 intermittent settings, it supplies ground to the internal windshield wiper motor module intermittent speed inputs, and the windshield wipers will continuously cycle for a single sweep followed by a delay of approximately 1 to 21 seconds, depending on which intermittent setting has been selected. When one of the intermittent settings is selected, the internal windshield wiper motor module starts an intermittent cycle by grounding the run/park relay coil, which activates the relay, and provides 12 volts to the low speed input of the wiper motor, causing the windshield wiper motor to cycle. When the windshield wiper motor reaches the end of an intermittent cycle, the position of the windshield wiper motor armature will cause the Hall-effect sensor to generate a voltage signal. When the wiper motor module detects the voltage signal generated by the Hall-effect sensor, it will simultaneously start a delay timer and deactivate the run/park relay, which disconnects voltage to the windshield wiper motor, leaving it parked. The windshield wipers remain parked until the internal windshield wiper motor module delay timer completes, and the next intermittent windshield wiper cycle starts.

Software Safe Mode
The windshield wiper motor defaults to this mode when the Hall-effect sensor voltage signal is lost. This can be caused by an obstruction of the windshield wipers, a binding linkage or an electronics concern. The motor will operate in either low or high speeds; INTERMITTENT mode is not available. The windshield wipers will not park when SOFTWARE SAFE mode is active. The windshield wipers can be parked by quickly changing the wiper switch from the OFF to the LOW speed position until the windshield wipers reach the parked position.

Windshield Washer - Five Hundred and Montego
The windshield washer is activated by the internal wiper motor module when it receives a ground signal from the wiper switch wash circuit. The internal wiper motor module activates the internal windshield washer relay by grounding the relay coil. When the relay is activated, it connects 12 volts to the washer pump, which is grounded to the chassis through circuit 1205 (BK).

Windshield Washer - Freestyle
The windshield washer is activated by the internal wiper motor module when it receives a ground signal from the wiper switch wash circuit. The internal windshield wiper motor module activates the internal windshield washer relay by grounding the relay coil. When the relay is activated, it connects 12 volts to the washer pump, which is grounded to the chassis through the rear wiper motor and module assembly.

Rear Window Washer - Freestyle
On Freestyle vehicles, the windshield and rear window washers are supplied with washer fluid from a single washer reservoir and pump, which are located in the engine compartment. The Freestyle windshield washer and the rear window washer are activated by their respective internal wiper motor modules when they receive a ground signal from the wiper switch to either the windshield or rear window washer inputs. Voltage polarity is reversed by either the windshield or rear window wiper motor and module assemblies to achieve directional change of the washer pump and washer fluid. Depending on which ground signal was provided, the windshield or rear window wiper internal motor modules activate either the windshield washer or rear window washer internal relays by grounding the respective relay coil. When either relay is activated, it connects voltage to the washer pump while the deactivated relay provides ground to the washer pump.

Rear Window Wiper and Washer - Freestyle
On Freestyle vehicles, the rear window wiper system consists of an integrated wiper motor and module assembly, which contains an internal washer relay. The rear window wiper motor and module is controlled by the rear window wash/wiper portion of the wiper switch. When the rear wash/wiper portion of the wiper switch is set to 1 of the 2 intermittent settings, the integrated rear wiper module will continuously cycle the rear wiper motor for a single sweep, followed by a delay. If the liftgate is opened while the rear window wiper is operating, it will stop immediately. The rear window wiper will resume normal operation when the liftgate is closed. When the rear window washer is activated, the rear window wiper module will simultaneously activate the rear window wiper motor, and the internal rear window washer relay. When the internal rear window washer relay is active, it connects 12 volts to the washer pump, which is grounded to the chassis through the windshield wiper motor and module assembly.

Smart Junction Box (SJB)
The smart junction box (SJB) is a wiper module that distributes or controls power to several electrical systems in the vehicle, including the wiper system.