I believe there is a separate valve under the slide that needs to be open when the ice maker is required to make ice. This is in a cold water line to the refrigerator and if I remember correctly it is a colored plastic valve with no tags on it. I located my valve on the rear corner of the drive side slide. The slide needs to be open in order to access this valve. I keep mine closed last time we used the unit; since we were not making any ice just had the unit out for 6 days and I did not see the point in opening the valve up yet.
2016 34RL CC; 2008 Ram Mega Cab 2500HD, 6.7L, 68RFE 6 speed, 4X4, Smarty S67