My driver's side rear windows stopped working. When I press the switch, I can hear the clicking sound from the solenoid, but it doesn't move. 

• I removed the door panel and pulled the plug to the motor. When I connected my gauges, I was able to see 12V in one direction, and -12V in the other direction (just as I would expect).
• The next step was to remove the entire power window regulator. I removed the motor from the slide and tested it from the window plug. No movement. When I connected a battery directly to the motor. The motor worked fine. 
• I reconnected the motor to the slide mechanism (and re-greased the entire unit while I had the opportunity). When running directly from the battery, it worked great in both directions. 
• I then re-installed the window regulator back into the truck. 

Now I'm chasing the electrical side, although I cannot figure out where the relay pack is. Does anyone know which relay or relay module runs the windows?
Any ideas on where else to look on this one? All of the other windows are working just fine.