Old-style 6.2L Glow Plug Controller Question

[nab407]

I'm almost done with my wiring harness restoration (praise baby jesus), but I have a question about the pinout for the "old-style" cylindrical '83 glow plug controller. I have all the wiring for it worked out, except for one mystery wire that has been cut. On all of the diagrams I've looked at, the pin the I have a wire coming out of, the diagram shows nothing there. Please advise.

In the image below, you will notice that the #2 pin has no wire coming from it. However, mine has a tan wire coming out of it, but it has been cut.