It does not sweat right away. Let it run for several minutes and it should start sweating. The large line (suction line) will be cold and the small line(liquid line) will be hot to the touch.
Is the unit putting out cold air? If you have a thermometer measure the room temp and measure the supply air temp. The supply (cold) air should be at least 15 degf to 20 degf difference.
1999 Bounder 34J, V-10, F53 chassis, Banks Power System, Safe T Plus Steering Control.