[projectRDM]

Sorry but you're wrong.

The S13 chassis has a single interior harness that runs from the passenger side of the dash over to the SMJ going under the hood, then back down the driver side of the car around the back and up to the passenger side Bpillar. It's a single harness. Though the power mirror switch is wrapped in a 'leg' of the harness, it is NOT separate and cannot be easily removed unless it's cut out. Base models cars are not prewired at all, so you have the option of either swapping the entire harness from a car that's power equipped or cutting the pigtails you'll need and running all the wiring from console to both doors on your own. There is no removable portion anywhere on the harness as suggested.
You could also take a power harness, fully unwrap every inch of it, remove and depin the wiring you need from the SMJ, and then repin it into your car, but that's still a lot of work and disassembly. At that point you're better off swapping the new harness in, you could then add power locks/windows, cruise, virtually anything easily if you wanted.