Need help with Fresh Water tank

[NateW]

Need some advice.

I recently bought this 2005 Designer 31 RLS. Needs some cleaning and a little TLC. But still good to go.

When I went to fill the fresh water tank. Water poured out the back. When I looked under the belly. I could see a line hanging down, not hooked to anything. When I turn the water on, it flows from there.

I dropped the water tank, and find two lines in the top. One gravity fill line (1.5" diam) and one smaller flex line plumbed to the top. I got the hanging water line attached to the flex line and I can fill up the tank!

But wait a minute. The water pump just keeps running... Oh ya, there is no way for the water to come back to the camper.
So here is my question. Should I have hooked the line up to the drain for the fresh water? I don't think that is how it should be. But how else will I get water back to the camper. Any help you can offer would be great. Was hoping to use it this weekend.

[NateW]

Here is a couple pics of the hook up.

[Redbird7]

That braided looking line is looking like a vent line for tank. The Pex line needs to hook to bottom of tank is it is a supply line to the pump. If it is on the pressure side of pump then is does not go to tank at all. Did you run water, where did it go?

[NateW]

The pex feeds water to the tank. I'm going to move it to the bottom to see if it will fill and also take water back to the pump.

The pex line runs water when I place it on city tank fill.