Here are a couple more pics in the daylight. As you can see, the led panel plug in the center is 3 pins. What Toy has done on the '10-'13 models is that they have made the turn signal socket a way to power up the rest of the tail lamp via a 5 wire harness. My tech and I believe that the sub-harness that I posted a pic of converts that 5 wire harness down to 3 wires and from there plugs into the tail lamp. If you look closely at the schematic you will see a a large plug at one end. I believe that this will mate with the existing 5 wire harness on our trucks. The other end contains 2 bulb sockets and what I believe to be the 3 pin male connector which will plug into the 3 pin female plug on the '14 tail lamp. You follow? My tech (who happens to be an ASE master) is 100% confident that all that is needed is this sub-harness.
With that said...I think I will be returning this. I wanted to get the tail lamp to finally solve this mystery once and for all. After ordering wheels and tires, and with the holidays coming up, I can't really afford to keep the tail lamp.