Try this,.... While holding the window button in the down position, make
a fist and rap on the interior door panel firmly (don't break the pannel, or
hurt your fist). If the window starts to work, it will probably work for a
couple of weeks. When GM window motors get tired, they have dead spots on
the motor armature. Giving a sharp rap on the door panel while holding the
button down, will sometimes get it to work again. If it starts working, you
will need a new window motor for that door. I have seen this many times.
I hope this helps you,