Is this factory 1975 stuff

Choke stove is plugged in to the control, as is the other wire that comes out of the harness next to my mystery wire in the pic. Fender top indicator connections are accounted for in the headlight harness as they should be, but it IS the same style connector. I also have the other connector that you showed ( not plugged in) as well as one by the battery in same harness , before the horns. I have a 74 manual (not 75) - not identified in there from what I have deciphered.
I actually have the parts of the harness in a garbage can in the shed, and I tagged what I thought I needed. I honestly have no idea what that is. There's a lot of plugs, but nothing single pole like that.Sorry.