HELP No water psi after de winterizing 2006 cross county

When your motorhome was winterized I assume you have a tube that was used to draw the anti freeze into the coach and through all the lines. I suspect that when you or whomever winterized the coach was finished they did not turn the valve to close that tube and connect the water tank. As a result no pressure. The valve is between the water tank and the pump and should have a clear tube attached.