Yes to the RH/LH.
My fault on the #57. The black ground you're looking for is PIN 20. Ground point of the wire remains the same.
I've never taken the dash off any of my foxes (yet), but I've taken quite a few off other cars, and I've never seen any ground wires up high near the glass (indicative of the word "cowl"), so I'm gonna assume my info here uses the word cowl in place of "kick panel", IE the piece of plastic that runs between the edge of the glove box, and the floor, where the ECM is. Unfortunately I don't have any location diagrams, only words.
Use paragraph #3 of this link
to properly test the grounds. Just because a test light lights up, doesn't mean its good.