Yup, that's the temp sensor, or what's left of it looks broken off.
I don't don't have clue as to the connector but judging by all the cut wires it's probably gone.
Dunno if it was in that missing harness or not.
Happy hunting, sorry but I couldn't find any instrument wiring in the FSM to give you a color code.
I would have looked at my '91, but it isn't here, got issues of my own.