Wiper and Washer Systems: Description and Operation
INTRODUCTIONThe windshield wiper system is unique to the Viper because of:
- The windshield design
- The overlap of the windshield wipers
- A wiper control module that regulates the operation of the wipers.
- An overload protection for the motors that turns the wiper motors OFF.
The wiper system consist of:
- Driver (D) and passenger (P) side wiper motors
- Wiper switch assembly
- Control module
- Wiring to all components
- Driver (D) and passenger (P) side wiper arms and blades
- Motor covers
The wiper control module governs all modes of wiper operation:
- Intermittent
- Mist
- Low speed
- High speed
Wiper System:
The module also synchronizes the wiper arm/blades operation, so they do not make contact with each other.
For the module to control the operation of two motors, it must sense the position of the wiper blades. The position is sensed by two switches built into each wiper motor that indicate when the motor is in the reversal, or park positions. After determining the switch positions, the module uses a motor speed signal to synchronize the wiper operation.
The synchronization process compensates for the speed difference between the two motors. This prevents the wipers from contacting each other. To keep the motors synchronized, the module continues to use the motor position switches to determine the position of the wiper arm/blades on the windshield. Once the wiper arm/blade has reached the reversal (park) position, the module stops the motor until it senses that both motors have reached the reversal (park) position. The module then resumes the wipe cycle. The combination of the speed signal and the position switches keep the control module informed of the exact position and speed of each wiper arm/blade.
When the module starts the wiper process the module controls the driver's motor first because the driver's arm/blade is on top of the passenger's wiper arm/blade. During start-up the module senses the driver's motor position switches to indicate that the wiper arm has moved. If the driver's arm/blade is position below the passenger's arm/blade, the module senses an overload condition and turns the wipers OFF.
Two-speed electric windshield wiper motors with intermittent wiper system are standard equipment. The intermittent system provides a pause between wipe cycles for use during conditions of very light precipitation.
The windshield wipers can be operated with the windshield wiper switch only when the ignition switch is in the ACCESSORY or IGNITION position. The fuse located in the fuse block module protects the circuitry of the wiper system and the vehicle.
The intermittent wipe system has a low and high speed with a delay mode. The delay mode has a range of 2.5 to 12.0 seconds. This is done by a variable resistor in wiper switch and is controlled electrically by a relay
The wiper system completes the wipe cycle to park when the wiper switch or ignition switch is turned OFF. The blades park in the lowest portion of the wipe pattern.
SYSTEM OPERATION
Windshield Washers
All models are equipped with electric operated windshield washer pumps. The wash function can be accessed in the OFF position of the wiper control switch. Pushing the wash switch level, when the switch is in the OFF position will operate the wipers and washer motor pump continuously until the washer button is released. Releasing the button will stop the washer pump. The wipers will complete the current wipe cycle followed by an average of two more wipe cycles ( +/- 1) before the wipers park and the module turns off.
Windshield Washer Nozzles
The washer nozzle are mounted on the wiper arms and are not serviceable. If nozzle performance is unsatisfactory the wiper arm will need to be replaced.
Wiper Blades
Wiper blades exposed to the weather for a long period of time tend to lose their wiping effectiveness. Periodic cleaning of the wiper blade is suggested to remove the accumulation of salt and road film. The wiper blades, arms and windshield should be cleaned with a sponge or cloth and a mild detergent or nonabrasive cleaner. If the blades continue to streak or smear, they should be replaced.
CIRCUIT OPERATION
Windshield Wipers
The windshield wiper on this vehicle is unique due to the windshield design and the overlap of the wiper blades.
The wiper system consists of: driver and passenger wiper motors, a wiper feedback RPM signal for each wiper motor, wiper switch, and control module.
The wiper module controls all modes of operation, and also synchronizes the wiper blades so they do not make contact with each other.
Battery feed for the wiper motors and the wiper control module is supplied on circuit F13. This circuit is protected by a 20 amp fuse in cavity 19 of the fuse block, and HOT at all times.
Power for fuse 19 is supplied on circuit A5. This circuit is protected by a 30 amp fuse located in cavity 13 of the Power Distribution Center (PDC).
A battery feed is supplied to the wiper control module on circuit V6. This circuit is HOT when the ignition switch is in the ACCESSORY or RUN position. Circuit V6 is protected by a 15 amp fuse in cavity 3 of the fuse block. Power for the fuse is supplied by circuit A31 from the ignition switch.
For the wiper module to control the wiper motor's operation, it must sense the position of the wiper blades. The position is sensed through two switches built into each wiper motor that indicate when the motor is in the reversal (UP), or the park position (DOWN). After determining the switch positions, the module uses a motor speed signal to synchronize the wiper operation.
The synchronization process compensates for the speed difference between the motors. This prevents the wiper blades from contacting each other. To keep the motors synchronized, the module continues to use the motor position input.
Intermittent Wiper Signal
The V7 circuit provides a variable voltage signal to the wiper control module when the operator has turned the intermittent wiper switch ON. Ground for the switch is supplied on the V17 circuit to the control module from the switch.
Low Speed Signal
Circuit V3 provides a ground path for the switch when it is in the LOW speed position to the control module.
High Speed Signal
Circuit V4 provides a ground path for the switch when it is in the HIGH speed position to the control module.
Washer Switch Signal
The V10 circuit provides a ground path for the switch when it is in the WASH position to the control module.
Motor Switch Signals (Drivers Side)
Circuits V45 and V48 provide the wiper control module with information on the position of the driver's side wiper arm. Circuit V45 is used for switch 1, and V48 is used for switch 2.
Motor Switch Signals (Passengers Side)
Circuits V46 and V47 provide the wiper control module with information on the position of the passengers side wiper arm. Circuit V46 is used for switch 1, and V47 is used for switch 2.