In case you need to snug up the sun roof, here is the manual over ride method.

 

I have a 2003 Discovery. 126,000. Front sunroof works fine. Rear sunroof does not operate.

I removed the rear sunroof motor and tested. Rear sunroof motor is operation.

I swap the roof (headliner) switches and the front sunroof operates perfectly. Therefore I have determined the switches to be fine.

Does anyone know if the rear sunroof operates on a different relay/fuse? Is there some hard to see ground wire that perhaps I am missing?