i found out how to do it.
A 1994 Mercury Villager, also known as a Dodge Caravan, can have its rear hatch removed by detaching the pistons which hold it to the body of the van. The pistons will be held by screws and removing them will allow the hatch to easily come off.
There is no separate switch for it. Pushing the light switch will defeat the dome and courtesy lamps.
Remove the wiring harness from the back of your 1993 Mercury Villager windshield washer motor pump. Remove the windshield washer pump hoses. Remove the windshield washer pump retaining bolts. Reverse the process to install your new windshield washer motor pump.
It's on the top back corner of the transmission.
Turn the key to the right.
Under the car by the back axle.
On the top of the transmission housing at the back corner.
Pull the clips back and lift them off.
Attached to the back side of the throttle body.
It's at the top of the transmission on the back corner.
In the ceiling housing for the rear A/C.