If you haven’t finished putting the tailgate window assembly back together yet, (hoping), check out the thread here today about repairing a window motor. I think it is the same thing and you should do that before buttoning it all up. Also in the technical threads list there are discussions about improving the wiring and troubleshooting that rear window setup. Hope this helps. I admire your dedication and workmanship and am looking forward to more of your interesting and well written posts. Use white lithium grease on those rollers and rails.