Well, that was a bust. The new ignition switch harness doesn't match the existing one. The existing one has two wires that come out of the large connector (with the 7mm bolt) under the dash, and go up above the steering column, presumably to another connector. I haven't been able to get to the top of the column to see where it goes, but it doesn't matter at this point; the harnesses don't match. I'm sending it back to Rockauto, but have been unable to locate a proper replacement. Not sure what to do at this point, except leave the original in place and work on the other variables.