On my 1998 Georgie Boy Cruise Master the tank was under the bed at the rear of the motorhome. It was a translucent, white tank and if you used a bright light you could see how far up the water level was. Ours did have the fill valve from the city water connection, same as The Bar's. It is possible that your tank is completely full as it would be difficult to see with the level at the very top. It is also possible that your tank level indication isn't working. If you turn off the water supply and close the tank fill valve you can then turn on the water pump and see if it puts water to the faucets.We think we found the water tank under one of the beds but has no water in it