Have a 2000 XJ Sport, and nothing in the tailgate works.... defroster, wiper motor or lock mechanism. I have power at the switches, any one know where in the car the wiring for the tailgate runs before I start ripping out the entire interior??

 

Sounds like you have a bad ground. Open up the trim panel where the wires for the hatch enter the body and see if you have a ground there. If not you can take the interior panel off of the hatch and run a ground to the wiper motor to see if that will get it going.

 

black grommet at the top more toward the drivers side. i had no 3rd brake light or plate light. found 2 broken wires in that grommet. hope this helps.

 

Open the hatch and look in the "crease" between the roof and the hatch, find the rubber tube, just take a peek at that to see if its ripped open and wires are broken.

Ive seen that happen more than once, its easier to look there before tracing wires.