harness under passenger seat?

I was doing some cleaning and found this small harness with a black connector coming out from under the carpet on the front passenger seat.  I couldn't find where the harness would attach to.  I don't know if the '07 3500 passenger version ever has power seats or heated seats.  Could it for the weight sensor for the airbag?  I bought the van used but the harness looks very factory.  Any idea?? Thanks

I believe that is for the seat belt warning light that is on the dash.