Power windows, door locks & fuel pump share a common ground at the driver's side ground bus. Pull the metal bar from the connector & clean the metal bar and female terminals inside the connector. Apply some dielectric grease to help prevent future corrosion. Here's a link to an article that has some pics showing the location of the ground bus. BTW - it's the connector where all the black wires meet. Let us know what you find.
http://www.bonnevilleclub.com/forum/...=article&k=102