The connector at each window motor should have two contacts- one with 12v+ and the other ground to make the window go one way, and reversed polarity to make the window go the other way. Unplug the motor connection and check to see if that's what you get on the connector that plugs into the motor when pressing the switches. If you have power at these connections suspect bad window motor. If there's no power suspect bad window switch. I don't know about the 'burb, but typically power and ground go through the drivers door switch first before going to the rear door switch, so if neither switch is working you should suspect the drivers door switch.