No water flows when operating the pump handle on '02 248 Voyager equipped with Marine Head /Manual Pump out . Approx 3/4" of residual water in bottom of bowl. When pumping handle, looks/sounds like just air is being pumped into bowl. Have confirmed marine head inlet seacock is open(handle in vertical position) Also, the wet/dry bowl selector decal is unreadable. Which position is "wet" versus "dry" for the selector switch,e.g. selector in vertical position - wet OR dry?