DRL Relay Block Location and Pictures

My truck does not have the Relay Block but it has the harness with the loop-back plug.   The blue arrow points to it's location.   
Note: More info on how to access the wiring harness below the diagram.

You can access the wiring harness from the top of the dash.   You will notice an access panel that can easily be removed (Careful not to mess up your dash)

After removing the access panel, you can see where the DRL Relay block would go:
The Red arrow is showing the loop-back plug.  The Blue arrow is showing the RPO Relay Block.  The Yellow arrow is showing the the harness where the Autolamp module goes (Not even going there!).