According to the wiring diagram, the connector to the ambient light sensor is part of the "Instrument Panel No. 2 Wire". This harness connects to the main harness "Instrument Panel Wire" via connection FG1 (located against the firewall, behind the instrument cluster). "Instrument Panel Wire" connects to the Main Body ECU using connection F9.
Blong, according to your pictures, F9 is the second harness down (in the second picture), which has a black white and green wire at the top. The black wire is cavity 6, the green wire is cavity 18, and the empty cavity to the right is 30. If the harnesses were connected all the way through, you should see the light sensor connect on cavities 20 (pink), 21 (red) and 22 (blue). Counting from the top right of that connector is cavity 30, below that is 29, below that is 28. Unfortunately its not clear in your picture if cavities 20, 21 and 22 are populated.
My guess is that you are missing the connectors between FG1 and F9, even though you have the harness between FG1 and the light sensor.
(What else would be interesting is if anyone who is missing the harness at the light sensor does have the harness between FG1 and F9).
In either case, it may be possible to just create a harness to connect directly from the light sensor to the main body ECU, no need to go through FG1 unless someone wanted to source out those terminal part numbers, and rip their entire dash apart. To make this bypass harness, one should be able hack the 4th gen harness light harness (82142-35020) and extend the wires directly down to the main body ECU, connecting them into the F9 connection using the proper terminals. Unfortunately, I don’t have the part numbers of these terminals. Does anyone know what these terminals part numbers are?
On a similar note, it appears cavity 28 is not connected on the F9 harness, according to the wiring diagram, this is the connection required for automatic headlights to be controlled via the ambient light sensor (which according to another thread was thought to be Body ECU programming). If this connection is added in addition to the ambient light sensor, factory “Auto Headlights” might be possible.