Door courtesy light lead question

The courtesy light lead for both doors terminates with a male bullet with a female bullet spliced together with it where it connects with main harness at the door/dash pillar. I cannot find any lead to connect to this female bullet on my harness or in the electrical diagram. The lead is (53) black with blue stripe. Is this left for another use or am I missing something? 1969 XR7 with AC and Power windows, FMX.

Yes, the female bullet is used for other applications: sail panel lamp as an example.

I just found the harness that connects to the two leads. I had disconnected it while running the harness back to the tail lights ect. It was underneath my wiring manual!!!

Well, that harness turned out to be the center console harness. My A pillar courtesy light harness on the passenger side has a black/white stripe wire that terminates with a male bullet plug with red insulation. A corresponding Red female bullet plug terminates on the harness that runs across the lower dash. Wiring diagram indicates the pillar courtesy light harness should be black/blue stripe with a male bullet and a female bullet spliced to it. This would allow me to connect with the male bullet with the spliced female bullet from the door courtesy light and to the two wire female bullet at the end of the harness coming across the dash from the drivers side. I am still confused! Is the spliced female bullet on the lead coming from the door courtesy light not used in my application?

Here are some photos showing the empty female bullet on driver and passenger sides.

I wouldn’t worry too much about that unused plug; Mustangs and Cougars often have unused plugs that are otherwise used for various optional accessories.

Sweet. It was driving me nuts figuring out if I was missing a male bullet lead on both sides. Now I can put the lower dash back in place and move forward. My eyes hurt from scanning the wiring diagrams repeatedly for something I missed! Thank you for the invaluable help!