[Richard]

The solenoid of most concern is the bedroom retract. I know that is counterintuitive because you want the bedroom to extend. But there is a check valve in the cylinder, and if there isn't pressure on the retract line, the cylinder will NOT extend. I tried to move a bedroom out once with a porta power until I learned this.

When you think about it, it's pretty clever. With that style system, if you lose all hydraulic pressure while driving along, the room will not fall out the side of the coach.