Originally Posted by Flybob
If it is not closed tightly the vibration will allow it to open especially if there is another window or vent that allows air to enter RV while moving.
Thanks, I cranked it tighter and it stayed closed for the last short trip to the scales. I'm heading out fo a couple hundred miles this weekend, I'll see what it does. It cranks so easily, It's, as you said, vibrating and the pressure differential is allowing it to lift open on it's own. I didn't have any windows open however.