Rear window washer does not spray fluid. When I push the rear window washer button, the front washer/wipers turn on. The rear wipers work normally.

From the 2013 operators manual;

Push the windshield wiper lever forward to spray washer fluid on the rear window. The lever returns to its starting position when released.

The windshield washer reservoir is used for the windshield and the rear window. Check the fluid level in the reservoir if either washer is not working.

Rear Wiper/Washer System Components
The rear wiper/washer system consists of the following components:
• Rear wiper/washer switch
• Window wiper module-rear
• Window washer pump-rear
• RR WIPER 15A fuse
• RR WPRB 25A fuse
Rear Wiper/Washer System Operation
The rear wiper module controls rear wiper motor operation. Battery voltage supplied to the module 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 wiper/washer switch is used to supply the rear window wiper and washer switch signal circuits. In wiper switch positions 1 and 2 the wiper switch signal circuit voltage level to the wiper motor module determines the wiper motor delay interval. The rear window washer pump supply voltage circuit is used to provide the operating voltage for the rear washer pump for as long as the rear washer switch is pressed. The rear window washer switch signal circuit is used as a wash signal to the rear wiper motor module to operate the wipers during the rear wash operation.


Did you replace the rear wiper module ?

There is a electric motor that pumps washer fluid . Located in the bottom of the washer fluid tank .
Wash Operation (Front and Rear Wipers)
The front and rear washer systems use the same windshield washer fluid pump. When either the front or rear wiper is in the washer position voltage will be supplied to one side of the windshield washer fluid pump (depending on whether it is front or rear), while the other side of the pump is grounded.
At this point, the windshield washer fluid pump sprays solvent onto the windshield. When the front or rear washer is activated, the BCM receives an input from the switch that is activated. The BCM will control the wipers while in the WASH mode. The BCM will control either the front wiper relay or the rear wiper relay to turn on the wipers. The windshield wipers operate at low speed for 3 swipes and returns to the park position.

When turning on the washers do you hear the motor run ? Have some one try it while you listen at the washer fluid tank ! These pump motors do go bad .
turn OFF the ignition.
Disconnect the harness electrical connector of the windshield washer fluid pump.
Connect a test lamp from the windshield washer pump control circuit to a good ground .
Turn ON the ignition, with the engine OFF.
Press the front washer switch.
Does the test lamp illuminate?
YES or NO !

GMC Acadia Forum: Front washer fluid not working. Help?

www.acadiaforum.net > ... > Problems, Recalls, TSBs, FAQs & Links

Dec 3, 2010 - 17 posts - ‎12 authors
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Hey Barry, go to your local O'Reilly's, Autozone, or Advance Auto and tell them your issue and ask them for their recommendations..... they WILL help you and it will be much easier than listening and trying to understand what I (or anyone) says on here..

1999 blazer i m pretty sure uses the same reservoir, its easy to check, look at bootom of res and there should be to pumps. a good way to test wiring and washer button is to wire the rear to frt and hit rear washer button and it should spray frt window, or just use a test light and check for a good ground and power when button is hit hope this helps.

your rear wiper motor might be faulty,in the front i would check your fluid level-if it is full and you hear the pump running-check your washer lines to see if they are pinched-usually around where the hood closes

Probably need to replace the pump. Separate pumps for front and rear. Check with a test light to see if there is power to the pump. If it has power but won't work, replace the pump. If no power, you have a wiring issue. Be sure to turn the switch on and have someone push the washer button when you are checking for power. There won't be any until you push it to "wash".

The switch for the rear wiper is on the actual windshield wiper switch for the front wipers, you have to push the lever forward to turn it on and then again to turn it off, to use the washer fluid for the rear wiper you push the same lever forward and hold it there till the washer fluid comes out.

The reservoir is the same one for the front washers. There are two electric pumps on the base of the reservoir (one for front and one for rear). You probably need a new pump. It is accessible behind the panel in front of the front right wheel.