We have a Pilgrammage International Open Road Series model 396 4S-5 andcannot find a manual or schematics for it anywhere as they are out of business. We are having trouble getting the kitchen sink to drain. We have drained the Graywater and Blackwater, run a snake through the kitchen drain,….. It appears that there may be a separate holding tank for the sink. The electronic indicators for the tanks say Wastewater, Sewer, Galley, and Freshwater. The galley indicator is full but we cannot find a drain for it anywhere. Any ideas? Does anyone have schematics they could send?