Windshield washers don't always shut off

If the windshield wipers on your 2002 Corvette won't shut off, it could indicate a problem with the wiper control switch or a malfunction in the wiper motor circuit. Here are some troubleshooting steps you can try:

1. Check the wiper control switch: Ensure that the wiper control switch is in the "Off" position. Sometimes, the switch can get stuck or malfunction, causing the wipers to stay on. Try moving the switch back and forth a few times to see if that resolves the issue.
2. Inspect the wiper motor relay: The wiper motor relay controls the power supply to the wiper motor. If the relay gets stuck or fails, it can cause the wipers to stay on. Locate the wiper motor relay in the fuse box or relay panel and try replacing it with a known working relay of the same type to see if that resolves the issue.
3. Check the wiper motor circuit: The wiper motor circuit may have a short or an electrical problem that is keeping the wipers engaged. Inspect the wiring harness connected to the wiper motor for any signs of damage or loose connections. Use a multimeter to check for continuity and proper voltage in the circuit. If you are not familiar with automotive electrical systems, it is advisable to consult a professional technician or a qualified electrician.
4. Disconnect the battery: As a temporary solution, you can disconnect the negative terminal of the car battery to stop the wipers from running. This will disable other electrical components as well, so it's recommended as a temporary measure until the issue can be properly diagnosed and repaired.

Question edited for clarity. Part of duplicate question added.
Duplicate question deleted.
Question moved to model category.

This says Pulse Board or the Switch

https://www.google.com/search?q=2004+Pontiac+Montana+front+wipers+won%27t+turn+off

This says it does have a relay... but

https://www.google.com/search?q=2004+Pontiac+Montana+wiper+relay

Nothing shows where it is located.

https://www.google.com/search?q=2004+Pontiac+Montana+wiper+relay+location

Relay here

https://www.autozone.com/electrical-and-lighting/wiper-motor-relay

It may not be releasing, you can test if you can find it!

https://www.autozone.com/electrical-and-lighting/wiper-motor-relay

..

You didn't take into account the wiper switch is a input to the BCM - body control module ,or do you know that ? The BCM controls wiper one an wiper two relay's to turn on the wipers .
Wondering if it is the PCB or perhaps a physical problem? Guessing never finds the problem . Reading how they work in factory service repair info should be the first step for someone that doesn't know .
Intermittent Operation
Windshield wiper DELAY operation is a low speed wiper motor function with a variable delay interval between the wiper motor cycles. The DELAY interval is determined by a series of 5 resistors within the wiper/washer switch. During DELAY wiper operation, the signal circuit voltage is further reduced through the DELAY resistors. The body control module (BCM) monitors the voltage on the signal circuit to determine the delay interval between the low speed wiper motor cycles.
If the wiper switch is moved from a longer delay interval to a shorter delay interval, the BCM will command an immediate wipe cycle and reset the delay timer to the shorter delay interval.
Additionally, intermittent wiper operation is vehicle speed sensitive. As vehicle speed is increased or decreased, the wiper interval will also increase or decrease.

Low Speed Operation
When the wiper switch is in the Low position, voltage is supplied through an internal resistor to the signal circuit. The body control module (BCM) monitors the windshield wiper switch signal 1 circuit and energizes the wiper 1 relay which will operate the windshield wiper motor. The wiper motor will operate at low speed, since the wiper 2 relay is de-energized. Low speed can also be commanded with a scan tool by commanding Wiper Relay Cmd. ON and OFF.
High Speed Operation
In the High position, the windshield wiper/washer switch supplies voltage to both the wiper 1 and wiper 2 relay coils. This energizes both relays and allows battery voltage from the wiper 1 relay switched output to the switched input of the wiper 2 relay through its contacts and out the switched output of the wiper 2 relay to the high speed circuit of the windshield wiper motor. The windshield wiper motor will operate at high speed. During HIGH speed wiper motor operation, the wiper switch signal circuit is at the LOW speed signal voltage, and the body control module (BCM) supplies redundant voltage to the wiper relay via the wiper diode.

Wiper/Washer System Components
The Wiper/Washer System consists of the following components:
• Windshield wiper/washer switch
• Body control module (BCM)
• Wiper 1 relay
• Wiper 2 relay
• Wiper diode
• Windshield wiper motor
• Windshield washer pump
• Windshield washer nozzles
• Windshield washer solvent container
• Windshield wiper arm and blade assemblies
• Windshield wiper transmission
• WIPER/SW 10A fuse
• WIPER 25A fuse
Refer to Master Electrical Component List.

DTC B3715 02: Front Wiper Relay Drive Circuit Short to Ground
DTC B3715 05: Front Wiper Relay Drive Circuit Short to Battery or Open

Your best bet , take it to a qualified repair shop.

Your windshield wiper's are computer controlled by the BCM - body control module . The wiper switch is an input to the BCM , which energizes two different relay's to turn on the wiper's . Taking the vehicle to a qualied repair shop an having diagnostic's run would be your best bet , unless you have a professional scanner that can read DTC'S - diagnostric trouble code's in the BCM !
DTC B3715 00: Front Wiper Relay Drive Circuit
DTC B3875 00: Wiper High Speed Relay Circuit
DTC B3922 00: Front Wiper Function Select Circuit
This is always the first step in the diagnostic process . An if you do not know how they work ,reading factory service manual info. should be done .
Circuit/System Description
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.
Your best bet , take it to a qualified repair shop.

In the under hood fuse box , should have diagram inside the lid . Front wiper's or rear ? Front fuse # 36 - 25 amp. Plus Two relay's PCB hi and Wiper PCB relay . Wouldn't think this being fuse problem . Wiper switch , motor etc... The wiper's are control by a computer . BCM - body control module .

The windshield wiper/washer system consists of front and rear wipers. The front and rear wipers are operative when the vehicle is in accessory or run. The front wipers have 4 different modes: Mist, Intermittent, Low, and High. When the front wipers are in the intermittent mode, there are 5 delay modes to chose from, commanded by the windshield wiper washer switch through the body control module (BCM). The rear wipers has an only one mode.

If the fuse is bad , could have a short to ground or wiper motor pulling to much current (amps) . Fuse's don't just blow for no reason ! Could also have DTC'S - diagnostic trouble codes stored in the BCM .
DTC B3715
DTC B3873
DTC B3875
DTC B3922

DTC B3715 02: Front Wiper Relay Drive Circuit Short to Ground
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 different PCB relays which control the desired wiper speed, high or low.
DTC B3922 00: Front Wiper Function Select Circuit

The PCB relay's are non- servicable , replace fuse box . Soldered in Your best bet mit be to take it to a qualified repair shop .

The generic electronic module (GEM) responds to the windshield wiper control commands by interpreting inputs from the steering column multi-function switch. The speed dependent wipers will compensate for the extra moisture that accumulates on the windshield at higher speeds, except when the multi-function switch is in the INT 1 position. At higher speeds, the speed dependent feature shortens the delay between wipes when using the variable interval wipers. Delays will automatically adjust at speeds between 16 and 105 km/h (10 and 65 mph).
Testing should be done before replacing any parts . And if you don't know about (GEM) Control module controlled system's your best bet , take it to a qualified repair shop . The first place to start trouble shooting these systems is with a scan tool that can read GEM module codes .

B1840 Wiper Front Power Circuit Failure GEM GO to Pinpoint Test B . B1476 Wiper High Speed Circuit Motor Failure GEM GO to Pinpoint Test B . B1473 Wiper Low Speed Circuit Motor Failure GEM GO to Pinpoint Test B .
B1431 Wiper Brake/Run Relay Circuit Failure GEM GO to Pinpoint Test B . B1432 Wiper Brake/Run Relay Circuit Short to Battery GEM GO to Pinpoint Test B . B1434 Wiper Hi/Low Speed Relay Coil Circuit Failure GEM GO to Pinpoint Test D . B1436 Wiper Hi/Low Speed Relay Coil Circuit Short to Battery GEM GO to Pinpoint Test D . B1438 Wiper Mode Select Switch Circuit Failure GEM GO to Pinpoint Test B . B1441 Wiper Mode Select Switch Circuit Short to Ground GEM GO to Pinpoint Test C . B1446 Wiper Park Sense Circuit Failure GEM GO to Pinpoint Test B . B1450 Wiper Wash/Delay Switch Circuit Failure GEM GO to Pinpoint Test E . B1453 Wiper Wash/Delay Switch Circuit Short to Ground GEM GO to Pinpoint Test C . B1458 Wiper Washer Pump Motor Relay Circuit Failure GEM GO to Pinpoint Test F . B1460 Wiper Washer Pump Motor Relay Coil Circuit Short to Battery GEM GO to Pinpoint Test F .
If no codes are stored then you go here .

• The Wipers Are Inoperative

• Fuse(s).
• Circuitry.
• GEM.
• Multi-function switch (13K359) (wiper/washer switch).
• Windshield wiper run/park relay.
• Windshield wiper HI/LO relay.
• Windshield wiper motor (17508).

• GO to Pinpoint Test B .

Your best bet , take it to a qualified repair shop that knows how to trouble shoot problems like this . This is no easy diagnose's .

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

the dash lights is a lose ground or power connection the wipers could be a couple things there is a wiper relay that may be going bad or the wiper motor is going bad could even be both

Turn wipers to off then turn the car off. We have the same problem in our 1986 Pontiac parisienne brougham

ask around other owners but i think your switch is falty 9 years old not much of a job to fix 1 hour 2 if you know nothing about it