Got this out of a walkthrough by someone named Seorin:
You must solve a pressure plate puzzle in the east to open the passage to the
west. The correct order, with the plate furthest from the chest being 1 and
nearest being 4, is 3-1-4-2.
I always use walkthroughs for the puzzles in games, I like to play games not sit around trying to figure out the combination of something for a hour. No fun in that, I'd go back to school if I wanted to do that crapola.