my 2004 landy disco. sunroof is hard to open or close by motor. I opened motor and cleaned rust and oiled it. it looks ok to spin. But after I assembly it, it is hard to drive cable to open/close sunroof. I wonder if the motor lost power or drive cable needs to be replaced. Any idea for the best solution?
Thanks!

Check the obvious things first, such as the tracks and runners, make sure that they're properly lubricated.
It's not unknown for those motors to develop internal faults such as short circuit turns which then shows up as the winding gear appearing to be "weak"