under the hood, against the firewall left side, the front and back use the same container
No
The rear window wiper fluid comes from the windshield wiper fluid tank in the engine compartment on a 2001 Ford Escape
In the engine compartment passenger side.
The same reservoir as the front wiper fluid. If the rears is not working then it may be frozen or blocked.
The rear window wiper uses the same fluid reservoir as the front, it just has a separate rear window pump attached to the fluid bottle under the hood.
Most likely on the bottom of the washer fluid bottle. Where you add fluid. If the filler neck goes into the fender that's where it is. If the bottle is visible it may be on the bottom of that, if not there, it is part of the wiper motor.
The owners manual shows that the washer fluid for the liftgate is supplied by the reservoir for the windshield
wheel washer fluid reservoir windshield wiper windshield window
Most of the times the washer fluid goes into the same resirvoir as the front.
A electric motor that moves the (window) wiper to clean the window.
Front reservoir also serves the rear
My 2003 Sienna has one tank that is for the front and rear window. You might have a problem with your pump or something else. Does your front wiper work?