Help needed for new rebuild and unknown connector

[mark460]

On a 98 Suburban, I just rebuilt the engine. I got everything together, but I can't figure out where this connector goes. It doesn't go to the distributor, or the oil sendor at the back of the engine. I seem to remember that it goes somewhere behind the engine. I think when I was putting the engine in, I noticed part of the harness hanging near the firewall so I disconnected this connector, but I looked all over and can't find the mating connector. any ideas, or where it goes? Thanks