I hate an incomplete hijack...
» if you have an 80 series with factory leather interior, you'll find two unused connector housings in the right and left body harnesses, under the console, immediately below the forwardmost coin slots. Both connector housings mate with the respective OEM seat switches, designed for those coin slots.
» if you have an 80 series with factory cloth interior, you'll find one unused connector housing in the left side body harness, under the console, immediately below the forwardmost coin slots; the passenger seat just doesn't get any love.
Oddly enough, there are power seat connectors below both seats, regardless of which interior you got from Toyota.
I haven't checked, because I don't have one to play with, but rumor has it the LX450 doesn't have factory connectors wired into the body harness, either the dash harness or the RH/LH body harnesses. Odd.