sometimes the root cause for what you describe is other than the obvious components. A dirty or high resistance window switch cluster...perhaps one with spilled Coke in it will reduce current to the motor and hence inhibit function. This was true for example with my sunroof. The sunroof motor in my case was not getting full current because the switch was dirty and the roof would not function at times. A simple dismantling/cleaning of the switch resolved the problem. Many before me mistakenly replaced their sunroof motors only to find that it was a dirty switch which can be cleaned...not even necessary to replace the $50 switch. Mine looked perfect inside only the contacts were dirty.
HTH,
George