Assuming 300 series - If you take the electric window & door lock wiring out of the pillar - you can get inside enough to get to it. on the OS, the wire comes down from just above - side of the instruments / mirror switch area .... on the NS, then it's a bit more complicated because the wire comes from a splice at the RHS of the heater motor, and may either be part of the door loom - or be separate ....
Ok, I was in a similar situation years ago, when modifying the contract to accommodate the addition of door lighting the wire and connector fell through the hole and was go.
So if you remove the kick panel in the foot well and up and behind the pillar up where the hole is you should see the wire hanging loose, there’s a bit slack available so may see it straight away, theres a bit of metal work of the pillar an other wiring but u will find the wire, a touch may help.
So with a cable tie poked through the hole, tape the wire to it and retrieve the single wire. My book tells me the wire colour is purple/white.,