You can unhook the hose at the hood and blow back through it to dislodge the debris. And pull the reservoir out and clean it, if necessary. Or use compressed air to blow through the hose.
The rear window washer is fed from the front window washer tank in the engine compartment
It is the same reservoir as the front window washer.
On a 2001 Ford Explorer : The washer fluid for the rear liftgate window is supplied by the same reservoir as the windshield ( that is located in the engine compartment )
The pump is located either inside or on the outside of the washer reservoir.
According to the 2010 Ford Explorer Owner Guide the washer fluid for the liftgate is supplied by the same reservoir as the windshield
The washer fluid for the rear liftgate is supplied by the same reservoir as your windshield ( located in the engine compartment ) on a 1999 Ford Explorer
The washer fluid for the liftgate is supplied by the reservoir for the windshield according to the 2000 Ford Explorer Owner Guide
Starting with the ( 1997 ) model year of the Ford Explorer , the washer fluid for the rear liftgate window is also supplied by the reservoir in your engine compartment ( that is used for the front windshield )
should be the same reservoir as the front windshield wipers
According to the owner's manual , a 2004 Ford Explorer's liftgate washer fluid is supplied by the reservoir tank for the front windshield - Helpfull
On a 1998 Ford Explorer , there is a 7.5 amp fuse in location # 12 for the washer pump relay and power window relay , according to the owner's manual (Helpfull)
On a 2001 Ford Explorer , the windshield washer fluid reservoir is in the engine compartment , on the passenger side of the engine compartment ( it is the compartment towards the rear and is also used for the rear window washer fluid )