The window regulator is the last part you should choose to change, and the hardest part. With some Fords it's very dangerous too, like all 1st gen Explorers, because the large spring is wound up and the motor is holding it tight. Members have lost a finger with those.
The main switch panel itself is very old, that should always be replaced in any window problem at 20 years old etc.
The window motors have a gear assembly on one end which attaches to the window regulator. That group of plastic parts it eh built in weak link, the wear items which are supposed to wear more, and thus save the motor itself. The motors are very reliable, try to never replace those, aftermarket parts are inferior for those.
The motor gear assembly has three plastic pucks inside it, plus the outer plastic ring gear and other parts. Those three pucks should always be replaced whenever the motor is removed and the age of those is unknown or very old. The HELP section of all parts stores carry those, for about $7 a kit. They also have the full gear assembly if that is needed, those are more like $20 a set.
The wiring inside the door jamb of the driver's door is common to have breakage of any wire, the window wire and door lock wires seem to be the most common. So if replacing the needed old and wear parts doesn't solve the problem, it will likely be in the LF door jamb, or the relay box under the dash in the column area.
