Those older Supras are cool. The dealership I use when I need parts, they have some old Supras and Land Cruisers on display.
I thought of something about the seat and the only other thing I can think of is that either the connector at the plug or the wires are broken somehow between the switch and that one motor for the seat. It not priority now since I've got the seat set, but one of these days I'll have to see if I can maybe figure it out.