Your jack valves are not getting power. Not familiarwith the wiring diagram for the Itasca but it has to be something common to all four valves.
I would suspect a faulty ground or a fuse. You should measure voltage at the one of the four leveling solenoids to see if there is voltage after you initiate the leveling sequence.
The easiest way is to have someone manually operate one of the Jacks and trace back from there. Measure both sides of the Jack solenoid valve (1) 12v at both sides means an open ground, (2) no 12v means that the problem is toward the Jacks controlbox.
Good luck and let us know what you find. maybe someone on here has the wiring diagram and can tell you which fuse to look for.