Okay, so I've been toiling away on my 82 245 diesel to B23 gas conversion car and I'm trying to make sure that all of the wires are connected correctly. Bear in mind that I had to remove the car's diesel wiring harness and install one from my '84 (gas) parts car. Well I get to the back of the wagon and in the spare tire well there's this 2 wire plug with a brown and a blue wire just hanging there connected to nothing. So I go out to my parts car and I follow the mating plug and it goes down to the differential cover and goes into some kind of sensor on the cover itself. What is this thing and what is it for? Bear in mind that this is an '84 with a cable driven speedometer so it's not a speed sensor. Do I need this thing? I'd really rather not have to swap the cover over as I already changed the rear diff oil and put Redline gear oil in there and that stuff's not cheap. Thanks, Charles