Hummer H2. Manual - part 753

Fig. 44: Rear Wiper/Washer Switch 
Courtesy of GENERAL MOTORS CORP. 

2. Insert a flat bladed tool at the top and bottom of the switch assembly in order to remove the switch 

assembly.  

3. Pull out the switch assembly in order to gain access to the connector.  

4. Disconnect the electrical connector.  

5. Remove the switch from the I/P.  

Installation Procedure 

 

2004 Hummer H2 

2004 ACCESSORIES & EQUIPMENT Wipers/Washer Systems - Hummer H2

  

Fig. 45: Rear Wiper/Washer Switch 
Courtesy of GENERAL MOTORS CORP. 

1. Connect the electrical connector to the switch assembly.  

2. Push in the switch assembly until both tabs click in place.  

3. Install the trim bezel. Refer to Trim Plate Replacement - Instrument Panel (I/P) Accessory Left in 

Instrument Panel, Gauges and Console.  

DESCRIPTION AND OPERATION 

WIPER/WASHER SYSTEM DESCRIPTION AND OPERATION 

Windshield Wiper/Washer System Components 

 

2004 Hummer H2 

2004 ACCESSORIES & EQUIPMENT Wipers/Washer Systems - Hummer H2

  

The windshield wiper/washer system consists of the following components:

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Windshield wiper/washer switch that is part of turn signal/multifunction switch  

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Windshield wiper motor and module  

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Washer fluid pump - reversible  

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Washer fluid pump relay  

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W/S WPR 25A fuse  

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W/S WASH 15A fuse  

Windshield Wiper/Washer System Operation 

The windshield wiper motor module is part of the windshield wiper motor cover and controls wiper motor 
operation. The windshield wiper motor is a 2 speed motor and is operated at low speed in all modes except 
HIGH. The accessory voltage supply circuit to the windshield wiper motor provides the power for operating the 
wiper motor and the wiper motor module. The windshield wiper switch supply voltage circuit is a 12-volt 
reference from the wiper motor module to the wiper/washer switch. The WASH, MIST, LOW, and DELAY 
modes are controlled by the windshield wiper/washer switch through a series of internal resistors, and the 
switch position determines the point on the resistor assembly where the reference voltage is applied. The 
windshield wiper switch signal circuit supplies the signal voltage from the switch assembly to the wiper motor 
module which determines the operating mode. Windshield wiper motor high speed operation is controlled by 
the windshield wiper/washer switch through the windshield wiper switch high speed signal circuit. The 
windshield wiper switch high speed signal circuit is supplied 12 volts by the wiper motor module and when the 
wiper/washer switch is turned to the HIGH position the windshield wiper switch high speed signal circuit is 
grounded. 

The washer fluid pump is a reversible motor and is used to wash both the windshield and rear window. The 
washer fluid pump is controlled by the windshield wiper motor module through the washer fluid pump relay. 
The washer fluid pump relay coil and switch are supplied battery positive voltage, and during the windshield or 
rear window wash modes the wiper motor module grounds the washer fluid pump relay control circuit 
energizing the relay. When the relay is energized battery positive voltage to the switch side of the relay is 
supplied to the windshield wiper motor module through the washer fluid pump supply voltage circuit. The 
windshield wiper motor module also controls the voltage polarity of the washer fluid pump control circuits. 
During windshield wash operation the windshield washer pump control circuit supplies positive voltage to the 
washer fluid pump and the rear window washer pump control circuit is the ground circuit. 

Windshield Wiper Switch Signal to the BCM 

The windshield wiper switch signal 2 circuit from the wiper motor module is used by the body control module 
as a signal to turn ON the headlamps and parklamps during windshield wiper motor operation. This feature can 
be enable/disable through calibration. There are calibrations to enable/disable the parklamps, rear parklamps, 
rear fog lamps, front fog lamps, high beams, and low beams in any combination in response to this feature. The 
nominal value of the calibrations are parklamps enabled, rear parklamps enabled, rear fog lamps disabled, front 
fog lamps disabled, high beams enabled, and low beams enabled. 

Check Washer Fluid Message 

 

2004 Hummer H2 

2004 ACCESSORIES & EQUIPMENT Wipers/Washer Systems - Hummer H2

  

The Check Washer Fluid message is controlled by the instrument panel cluster using an input from the washer 
fluid level switch. The washer fluid level signal circuit is supplied ignition voltage through a resistor then 
monitored within the instrument cluster. The washer fluid level switch is normally open so the instrument 
cluster detects ignition voltage on the washer fluid level signal circuit whenever the washer fluid level is not 
low. When the washer fluid reaches the point where the driver should be informed that the washer fluid is low, 
the washer fluid level switch closes. When the washer fluid level switch is closed the washer fluid level signal 
circuit voltage is pulled low, and the instrument panel displays the Check Washer Fluid message on the driver 
information center. In order to prevent the Check Washer Fluid message from being displayed while sloshing is 
occurring in the washer fluid container, the instrument cluster is programed with a 1 minute delay before 
changing states of the Check Washer Fluid message during an ignition cycle. 

REAR WIPER/WASHER SYSTEM DESCRIPTION AND OPERATION 

Rear Wiper/Washer System Components 

The rear window wiper/washer system consists of the following components: 

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Rear window wiper/washer switch  

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Rear window wiper module  

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Washer fluid pump - reversible  

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W/S WASH relay  

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RR WPR 15A fuse - Fuse Block I/P  

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RR WPR 25A fuse - Fuse Block Underhood  

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W/S WASH 15A fuse  

Rear Wiper/Washer System Operation 

The rear window wiper motor module is part of the rear window wiper module and controls wiper motor 
operation. Battery voltage supplied to the wiper motor assembly is used to operate the wiper motor in all modes 
and to return the rear wiper arm to the park position after the ignition is turned OFF. Accessory voltage supplied 
to the rear window wiper/washer switch is used to supply the rear window wiper/washer switch signal and 
control circuits. In switch positions low and high the wiper switch signal circuit voltage level to the wiper motor 
module determines the wiper motor delay interval. The rear window washer switch signal circuit activates the 
rear window wiper motor wash operating mode, and the same signal is used to signal the windshield wiper 
motor module the rear window wash mode is active. 

The washer fluid pump is a reversible motor and is used to wash both the windshield and rear window. The 
washer fluid pump is controlled by the windshield wiper motor module through the washer fluid pump relay. 
The washer fluid pump relay coil and switch are supplied battery positive voltage, and during the windshield or 
rear window wash modes the wiper motor module grounds the washer fluid pump relay control circuit 
energizing the relay. When the relay is energized battery positive voltage to the switch side of the relay is 
supplied to the windshield wiper motor module through the washer fluid pump supply voltage circuit. The 
windshield wiper motor module also controls the voltage polarity of the washer fluid pump control circuits. 
During rear window wash operation the rear window washer pump control circuit supplies positive voltage to 
the washer fluid pump and the windshield washer pump control circuit is the ground circuit. 

 

2004 Hummer H2 

2004 ACCESSORIES & EQUIPMENT Wipers/Washer Systems - Hummer H2