Dave, I think Stan is saying that we don't need to pay attention to the arrows anymore, just follow his calibration video and all should be well. I believe the only wires in his video are going to the TIU output to power the tester at it's power inputs.
Edit: The arrows in Stan's mark up schematic would still tell you that 5vdc was present, but I believe the blue light does the same thing.
Maybe Stan will clarify this, or add to it, he words things much better than I do and he knows for certain what's happening too!
Edit again: Sorry Stan, I didn't see your post above? I must have been posting at the same time you were?