Have someone work the master switch (the one in the driver door) and go around to each other door and listen for the motor to see if it's running.
If you read through the thread willindsay posted, you'll see the usual culprit which are those goofy little nylon bushings that break down over time and through repeated use. Also pay attention to post #11 where he shows you that large black gear. Sometimes that gear will strip teeth off and that can cause the windows to not work as well.
I'm in the same boat. I had only one working window, the front passenger, and the other 3 are / were DOA. The driver window wouldn't do anything and I found out that the relay in the "Express Down Module" had literally broken all 4 solder points on the PCB due to vibration of the truck over time. Soldered the relay back to the board and my driver window works just dandy...even has the "One Touch Down" feature again. However, both rear windows don't work, but the motors run, so I'm betting I probably need a couple sets of bushings myself, but I haven't really been motivated enough to go out and fix it since colder weather is coming and we won't need to have the windows down anyway.
