94 Suburban My windshield wipers do not operate as they should: stop mid-cycle, do not stop when wipers turned off, will not dispense washing solution sometimes. The post on FixYa regarding the circuit board looks like it will solve much of the problem by either repairing or replacing the board. Question: will repairing or replacing the board address the problem of dispensing the washing solution? Any help much appreciated !!!

It should be a short circuit or a bad relay. Good luck.

Lose connections , Switch , BCM - body control module , wiper control relays . wiper motor going bad etc.... Taking the vehicle to a qualified repair shop to have it diagnosed would be your best bet . Could have DTC'S - diagnostic trouble codes stored in the BCM . There is nothing commom about these systems .

The windshield wiper/washer switch signal circuits are inputs to the body control module (BCM) and the BCM controls wiper motor low speed operation, washer pump and high speed operation. The windshield wiper/washer switch is provided a low reference from the BCM and each of the switch signal circuits is supplied 12 volts through a resistor and monitored within the BCM. During LOW or INTERMITTENT operation the wiper switch low signal circuit is closed to the low reference circuit through a series of resistors within the switch assembly and the signal circuit voltage monitored by the BCM will depend on the switch contact location to the resistor assembly. During HIGH or WASH operation the high and wash switch signal circuits are closed directly to the low reference circuit within the switch assembly and nearly all the signal circuit voltage will be dropped across the BCM resistors. The BCM controls the wiper motor through the WIPER CONTROL PCB Relay and the WIPER SPEED PCB Relay. During any wiper motor function that uses low speed the BCM supplies the voltage to energize the WIPER CONTROL PCB Relay and battery voltage will be supplied from the WIPER CONTROL PCB Relay through the de-energized WIPER SPEED PCB Relay to the wiper motor low speed control circuit. During high speed wiper motor operation the WIPER CONTROL PCB Relay is energized as in low speed and the BCM provides a ground to energize the WIPER SPEED PCB Relay and the battery voltage is supplied to the wiper motor high speed control circuit. Wiper motor park operation is controlled by the BCM using an input from the park switch within the wiper motor assembly. The BCM supplies the park switch signal circuit 12 volts through a resistor then monitors the circuit. Whenever the wiper motor is out of the park position the park switch signal circuit is closed to ground and nearly all the signal circuit voltage will be dropped across the BCM resistor. When the wiper switch is turned to the OFF position while the wiper motor is somewhere in mid-cycle, the BCM will continue to operate the motor until the wipers reach the park position. If the ignition is turned OFF while the wipers are in mid-cycle, the wipers will stop immediately where they are and the BCM will park the wipers the next time the ignition is cycled ON.

DTC B3715 02: Front Wiper Relay Drive Circuit Short to Ground
DTC B3922 00: Front Wiper Function Select Circuit

Yukon what ? just a plain yukon ? 2WD or 4WD XL - Denali etc...
No pulse board . controlled by the BCM - body control module . Taking the vehicle to a qualified repair would be your best bet .
Windshield Wipers
The windshield wiper/washer switch signal circuits are inputs to the body control module (BCM) and the BCM controls wiper motor low speed operation, washer pump and high speed operation. The windshield wiper/washer switch is provided a low reference from the BCM and each of the switch signal circuits is supplied 12 volts through a resistor and monitored within the BCM. During LOW or INTERMITTENT operation the wiper switch low signal circuit is closed to the low reference circuit through a series of resistors within the switch assembly and the signal circuit voltage monitored by the BCM will depend on the switch contact location to the resistor assembly. During HIGH or WASH operation the high and wash switch signal circuits are closed directly to the low reference circuit within the switch assembly and nearly all the signal circuit voltage will be dropped across the BCM resistors. The BCM controls the wiper motor through the Wiper Relay and the Wiper High Relay. During any wiper motor function that uses low speed the BCM supplies the voltage to energize the Wiper Relay and battery voltage will be supplied from the Wiper Relay through the de-energized Wiper High Relay to the wiper motor low speed control circuit. During high speed wiper motor operation the Wiper Relay is energized as in low speed and the BCM provides a ground to energize the Wiper High Relay and the battery voltage is supplied to the wiper motor high speed control circuit. Wiper motor park operation is controlled by the BCM using an input from the park switch within the wiper motor assembly. The BCM supplies the park switch signal circuit 12 volts through a resistor then monitors the circuit. Whenever the wiper motor is out of the park position the park switch signal circuit is closed to ground and nearly all the signal circuit voltage will be dropped across the BCM resistor. When the wiper switch is turned to the OFF position while the wiper motor is somewhere in mid-cycle, the BCM will continue to operate the motor until the wipers reach the park position. If the ignition is turned OFF while the wipers are in mid-cycle, the wipers will stop immediately where they are and the BCM will park the wipers the next time the ignition is cycled ON.

The PCB wiper relays are soldered directly to circuit board inside the under hood fuse box.
The windshield wiper/washer switch signal circuits are inputs to the body control module (BCM) and the BCM controls wiper motor low speed operation, washer pump and high speed operation. The windshield wiper/washer switch is provided a low reference from the BCM and each of the switch signal circuits is supplied 12 volts through a resistor and monitored within the BCM. During LOW or INTERMITTENT operation the wiper switch low signal circuit is closed to the low reference circuit through a series of resistors within the switch assembly and the signal circuit voltage monitored by the BCM will depend on the switch contact location to the resistor assembly. During HIGH or WASH operation the high and wash switch signal circuits are closed directly to the low reference circuit within the switch assembly and nearly all the signal circuit voltage will be dropped across the BCM resistors. The BCM controls the wiper motor through the WIPER CONTROL PCB Relay and the WIPER SPEED PCB Relay. During any wiper motor function that uses low speed the BCM supplies the voltage to energize the WIPER CONTROL PCB Relay and battery voltage will be supplied from the WIPER CONTROL PCB Relay through the de-energized WIPER SPEED PCB Relay to the wiper motor low speed control circuit. During high speed wiper motor operation the WIPER CONTROL PCB Relay is energized as in low speed and the BCM provides a ground to energize the WIPER SPEED PCB Relay and the battery voltage is supplied to the wiper motor high speed control circuit. Wiper motor park operation is controlled by the BCM using an input from the park switch within the wiper motor assembly. The BCM supplies the park switch signal circuit 12 volts through a resistor then monitors the circuit. Whenever the wiper motor is out of the park position the park switch signal circuit is closed to ground and nearly all the signal circuit voltage will be dropped across the BCM resistor. When the wiper switch is turned to the OFF position while the wiper motor is somewhere in mid-cycle, the BCM will continue to operate the motor until the wipers reach the park position. If the ignition is turned OFF while the wipers are in mid-cycle, the wipers will stop immediately where they are and the BCM will park the wipers the next time the ignition is cycled ON.

DTC B3715 02: Front Wiper Relay Drive Circuit Short to Ground
DTC B3875 00: Wiper High Speed Relay Circuit
DTC B3922 00: Front Wiper Function Select Circuit
Have it checked for DTC'S - diagnostic trouble codes .

The body control module (BCM) controls the wiper motor based on input from the windshield wiper washer switch. The BCM monitors the wiper washer switch through three separate signal circuits and a ground circuit. The windshield wiper switch high signal circuit is used to determine high speed wiper operation, the windshield wiper switch low signal is used to determine low speed, intermittent, and mist operation through the use of a resistor ladder, and windshield washer switch signal circuit is used to determine washer operation.
The BCM controls the windshield wiper motor through two output controls, controlling two relays which determine the desired wiper speed, high or low.
Your best bet , take your vehicle to a qualified repair shop or dealer . Hooking up a factory scan tool to see what the wiper switch inputs to the BCM are correct and outputs to relays are good .

When the windshield wiper / washer switch is turned to the OFF position while the wiper motor is somewhere in mid-cycle, the wiper motor module will continue to operate the wiper motor until the wipers reach the park position. If the ignition is turned off while the wipers are in mid-cycle, the wipers will stop immediately where they are. The wipers will park the next time the ignition is cycled to the ON position.

Schematic Reference: Wiper/Washer Schematics


1

Did you review the Wiper/Washer System Description and Operation and perform the necessary inspections?
Go to Step 2
Go to Symptoms - Wiper/Washer Systems

2

1. Turn the ignition ON.
2. Turn the windshield wiper/washer switch OFF.

Are the windshield wipers always on?
Go to Step 3
Go to Testing for Intermittent Conditions and Poor Connections in Wiring Systems

3

Disconnect the windshield wiper/washer switch connector.
Are the windshield wipers always on?
Go to Step 4 if yes
Go to Step 7 if no

4

1. Disconnect the windshield wiper motor connector.
2. Test the windshield wiper switch signal 1 circuit for a short to voltage. Refer to Circuit Testing and to Wiring Repairs in Wiring Systems.

Did you find and correct the condition?
Go to Step 11
Go to Step 5

5

Test the windshield wiper switch signal 2 circuit for a short to voltage. Refer to Circuit Testing and to Wiring Repairs in Wiring Systems.
Did you find and correct the condition?
Go to Step 11
Go to Step 6

6

Test the windshield wiper motor high speed circuit for a short to voltage. Refer to Circuit Testing and to Wiring Repairs in Wiring Systems.
Did you find and correct the condition?
Go to Step 11
Go to Step 9

7

Inspect for poor connections at the windshield wiper/washer switch. Refer to Testing for Intermittent Conditions and Poor Connections and to Connector Repairs in Wiring Systems.
Did you find and correct the condition?
Go to Step 11
Go to Step 8

8

Replace the windshield wiper/washer switch. Refer to Windshield Wiper and Washer Switch Replacement - On Vehicle in Steering Wheel and Column.
Is the repair complete?
Go to Step 11
--

9

Inspect for poor connections at the windshield wiper motor. Refer to Testing for Intermittent Conditions and Poor Connections and to Connector Repairs in Wiring Systems.
Did you find and correct the condition?
Go to Step 11
Go to Step 10

10

Replace the windshield wiper motor. Refer to Windshield Wiper Motor Replacement .
Is the repair complete?
Go to Step 11
--

11

Operate the system in order to verify the repair.
Did you correct the condition?
The Wiper / Washer System consists of the following components:
?€¢
Windshield wiper / washer switch

?€¢
Windshield wiper system module / motor

?€¢
Windshield washer fluid pump

?€¢
Windshield washer fluid level switch

?€¢
Instrument panel cluster (IPC)

?€¢
ACC 15-amp fuse

?€¢
WSW 30-amp fuse

Hey Derek , here is how the wipers park position is suppose to work !
Windshield wiper motor park operation is controlled by the body control module (BCM) using an input from the park switch within the wiper motor assembly. The BCM monitors the windshield wiper motor park switch circuit to determine if the windshield wiper blades are at the bottom of the glass. The circuit will be pulled to ground by the wiper motor park switch while the windshield wiper motor is operating. When the wiper switch is turned to the OFF position while the wiper motor is somewhere in mid-cycle, the BCM will continue to operate the motor until the wipers reach the park position. If the ignition is turned OFF while the wipers are in mid-cycle, the wipers will stop immediately where they are. The BCM will park the wipers the next time the ignition is turned ON.
The wipers will not park when they are commanded ON and OFF with a scan tool. The BCM will park the wipers the next time the wiper switch is turned ON and OFF.
The BCM provides stall protection for the wiper motor by monitoring the park switch. If the park switch does not transition for 3 seconds while the wipers are operating, the BCM will assume that the wiper motor is stalled, and will de-energize the wiper relay until the wiper switch is cycled OFF and ON again.
Check for a voltage signal on the yellow wire at the wiper motor assembly , this is signal to the BCM ! If there is no signal you need to replace the windshield wiper motor assembly ? If there is a signal need to have Tech 2 scan tool hooked up to see if The BCM is the problem ! Relay #39 an #40 are the high an low wiper relays in the under hood fuse block ! Do you have a volt meter ,do you know how to do electrical testing ?

Sorry , no adjustment .
Wiper/Washer System Components
The Wiper / Washer System consists of the following components:
• Windshield wiper / washer switch
• Windshield wiper system module / motor
• Windshield washer fluid pump
• Windshield washer fluid level switch
• WPR 25A fuse
Wiper / Washer System Operation
The windshield wiper motor module is part of the windshield wiper motor cover and controls the wiper motor operation. The windshield wiper motor is a 2 speed motor. Windshield wiper DELAY operation is a low speed wiper motor function with a variable delay interval between the wipe cycles. The DELAY interval is controlled through a series of resistors within the wiper / washer switch.
Park Position Operation
When the windshield wiper / washer switch is turned to the OFF position while the wiper motor is somewhere in mid-cycle, the wiper motor module will continue to operate the wiper motor until the wipers reach the park position. If the ignition is turned off while the wipers are in mid-cycle, the wipers will stop immediately where they are. The wipers will park the next time the ignition is cycled to the ON position.

Do you know how to do diagnostic's ?

Wipers Blades Do Not Park
Step
Action
Yes
No
Schematic Reference: Wiper/Washer Schematics
Connector End View Reference: Wiper/Washer Connector End Views
DEFINITION: This table diagnoses the wipers operate normally but will not return to the park position when the wiper operation is cancelled.
1
Did you perform the Diagnostic System Check - Vehicle?
YES - Go to Step 2
NO - Go to Diagnostic System Check - Vehicle in Vehicle DTC Information
2
Turn ON the ignition, with the engine OFF.
Move the wiper switch to the LO position.
Move the wiper switch to the OFF position.
Do the front wipers advance to the park position?
YES - Go to Testing for Intermittent Conditions and Poor Connections in Wiring Systems
NO - Go to Step 3
3
Turn the ignition switch to the RUN position.
Turn the wiper switch to OFF.
Disconnect the wiper/washer switch connector.
Do the wipers park?
YES - Go to Step 7
NO - Go to Step 4
4
At the wiper/washer switch connector, measure the voltage of the windshield wiper switch signal 2 circuit.
Does the voltage measure greater than 1.0 volts?
YES - Go to Step 5
NO - Go to Step 8
5
Reconnect the wiper/washer switch connector.
Disconnect the wiper motor connector.
Measure the voltage of the windshield wiper switch signal 2 circuit.
Does the voltage measure greater than 1.0 volts?
YES - Go to Step 6
NO - Go to Step 8
6
Repair a short to battery positive voltage in the windshield wiper switch signal 2 circuit. Refer to Circuit Testing and Wiring Repairs in Wiring Systems.
YES - Did you find and correct the condition?
NO - Go to Step 9
--
7
Replace the wiper/washer switch. Refer to Turn Signal Multifunction Switch Replacement in Steering Wheel and Column - Tilt.
YES - Did you complete the replacement?
NO - Go to Step 9
--
8
Replace the wiper motor cover. Refer to Wiper Motor Cover Replacement .
YES - Did you complete the replacement?
NO - Go to Step 9
--
9
Operate the system in order to verify the repair.
Did you correct the condition?
System OK
Go to Step 2

It sounds to me as though both of the wipers have slipped. The operation of the wipers sounds fine except they do not park in the correct location. To fix this, start the wipers and then turn them off to ensure they think they are in the parked location. At the base of each wiper there is a small cover that can be easily removed with a small screwdriver. Underneath each cover you will see a nut. Loosen the nut somewhat and reposition each windshield wiper to the proper park location. Once done, tighten the nuts securely but do not over tighten, then reinstall the caps. Cycle your wipers on and off a few times to ensure the wipers park correctly. I have owned a lot of vehicles and ALL of my GM vehicles have had this problem.

yes the wiper motor is probably at fault due to the self parking mechanism is internally in the motor.
well the rear one check fuses and then check for power at motor, if there is power at motor possibly motor again, if there is no power at motor when operating check wiring in flexible joint between body of car and back door/tailgate.

• Windshield Wipers Continue to Run When Turn Signal and Windshield Wiper Switch Are Turned OFF

• Damaged turn signal and windshield wiper switch .
• Damaged windshield wiper motor .
• Damaged windshield wiper control module.

Pin Number Circuit Circuit Function 1 57 (BK) Wiper Motor Ground (Park) 2 28 (BK/PK) Wiper Module to Wiper Motor (Park Switch) 3 65 (DG) Wiper Motor Power (Park Feed) 4 61 (Y/R) Wiper Motor Common (RUN) 5 56 (DB/O) Wiper Motor LO 6 58 (W) Wiper Motor HI
Windshield Wiper System The windshield wiper system consists of :

• Windshield wiper motor (17508) (F-type).
• Washer system.
• Windshield wiper control module.
• Turn signal and windshield wiper switch (13K359).

The windshield wiper control module is:

• Located at the instrument panel fuse panel.

The windshield wiper motor is:

• Attached to the cowl top extension (021A36) .
• Connected to windshield wiper mounting arm and pivot shaft (17566) .

The turn signal and windshield wiper switch features a:

• Rotary wiper switch.
• Push type washer actuator.

OFF/Low/High Speed

• Has a two-speed, permanent magnet, three brush electric windshield wiper motor .
• The windshield wiper motor has a brush rigging that permits selection of low or high speed.
• When the turn signal and windshield wiper switch is in the LO position, the common brush and the blue/orange wire brush are used, and the windshield wiper motor operates at low speed.
• When the turn signal and windshield wiper switch is in the HI position, the common brush and the white wire brush are used.
• In HI position, electric current will bypass a portion of the armature winding causing the windshield wiper motor to operate faster.
• When the turn signal and windshield wiper switch is moved to the OFF position, the windshield wiper motor will continue at low speed until the park switch outer contacts open.
• When the park switch contacts open, the windshield wiper motor stops in the park position.

Interval
When the turn signal and windshield wiper switch is in the interval position:

• The wipers make single wipes separated by pauses.
• The rotary switch is on the end of turn signal and windshield wiper switch .
• The length of the pause can be set from approximately 1 to 17 seconds.
• Length of pause decreases as the rotary switch is rotated away from off.
• Length of pause increases as the rotary switch is rotated toward off.

While in the interval wiper mode:

• It is normal to hear a slight click at the beginning of each on/pause cycle. NOTE: When using interval wipers, the first wipe may not occur until after a pause of up to 17 seconds.