drhank
OK....then lets move on the power source and the grounds.
Under the hood the ''battery 2'' has small relays, ( breaker ) #29 for the door module, and #33 ''battery 3'' for the top, check for the corrsion on the pins and its filament, that you can look into a tiny window of the relay if it is defective.
On the passenger side ( under the carpet ) check the fuse #45 for the auxiliary relay, if it is ok then check its relay that feeds the top module.
Lower the door '' A '' pillar the ground 201 ( black ) pack for the door and the components in this area, open the cover and check for pins corrsion or weak pins, also the female connections that do not makes proper contacs.
Then at the lower door ''B'' pillar ( behind the seat ) do the same, check the pack of 6 black wires and its conditions.
To access at those grounds.... the door sill cover ( press in ) has to be removed, ounce this is done then the front and rear trims are easy to removed.
The battery grounds (2) could be a source of problems, ground 104 lower the battery and ground 106 on the Instrument panel ( firewall ) .....the battery has to be removed.in order to limits shorts.... the ground connections and surfaces must deeply cleaned.....do this before checking the car grounds.
The windows will have to be reindex when the works is completed.... ( hoping that it willworks )
Since you are a dedicate DIY, on internet ( google ) down load a manual for the training of the GM mechanics, it is free and has all sorts of goodies inside....you will be please. ( thanks GM )
Good luck
IAN