^^^POWER OFF^^^ is the biggie. If that motor isn't actually dead, it can generate enough force to really hurt you.
If Motor is running and the Gear isn't turning, there's a kit you can get to replace damaged parts in the gearbox.
If Motor is NOT running a certain Ford Window Lift Motor is available at much less money than from Kwikee. The info's out here someplace, or a patient parts person could match it up for you.
Couple tips:
1. To TEST the motor, you apply 12VDC and Ground to the motor terminals. By that I mean the motor shell does NOT have to be grounded. The polarity you apply to the two terminals that the harness connects to is what determines Step In or Step Out.
2. In the Fords, the motors come in Left and Right, so you can check motors for both Driver and Passenger sides to look for your fit.
If God's Your Co-Pilot Move Over, jd
2003 Jayco Escapade 31A on 2002 Ford E450 V10 4R100 218" WB