The wire harness part no. you are asking about contains the actual LEDs that are being added for the glovebox; the 2017+ don’t include the glovebox LED at all. My splitter allows you to “split” the currently installed footwell-only LEDs to add a second string of LEDs for the glovebox lighting, all using the OEM Ford connectors. The LED harness has three LEDs, one you will use for the above-glovebox accent light on the dash, and the other two can be used for illuminating the glovebox interior (or just leave them unused behind the dash).
Let me know if you have any more questions, and PM me if you would like a splitter!