If it is electric it's switch is on the drivers door next to the switches for the front windows
On a 2000 Mercury Villager : The washer fluid for the rear liftgate is supplied by the same reservoir as the windshield ( located in the engine compartment )
Make sure the key lock under the rear window is turned to the door unlock position ,not the glass unlock position.
Just use a flat head screw driver to pry it off.
Have you checked the rear hatch glass ?? Open it and reclose it firmly.
Open the rear liftgate on a Mercury Sable wagon and you will see the rear window washer fluid reservoir fill plug near the bottom of the passenger side tail light
Press the button on the rear hatch that has the key hole in it. This will release the window catch and it should open when you try and lift the window.
On the rear side of the throttle body.
No such option was available.
The washer fluid for the rear liftgate is supplied by the same reservoir as the windshield in a 2000 Mercury Villager
There are several things that can cause your 1998 Mercury Villager rear fan to stop working. The most common cause is a disconnected or corroded ground wire.
If it has a rear orifice it's in the rear unit under the roof panel.
Conventional drum brakes.