just had exactly the same problems with our galaxy this is a bad earth, to fix it take off the door card peel back the lining under the card find the multi plug on the window motor find the brown wire at the end of the plug, to test take a earth straight from battery to the brown lead ( may have to peel back some insulation ) this should work ours did, if this works then you need to trace your earth fault or put in a new earth.
Bedford Man, March 2008