Anybody with a 318SAB. Looking at this one, it has 76 gal gray, 38 waste but only two tank handles, are the two gray tanks connected to one drain? (Assume there are two)
I used to own a 2013 318SAB model. We had one gray water valve that served both gray tanks (kitchen/bath) on ours. It was easy to see the connecting wye on the 2 gray lines right behind the valve. Separate black water valve as you know