I'll admit that I don't have a Rushmore nor a Whirlpool frig. But in my SOB with the residential style Fridgidaire, there is a cover that covers the ice maker. You pull that cover off and there's an off/on rocker switch that powers the ice maker. This is also where you'll find the little control arm that sits over the ice bin.
In most instances, you'll turn the water on (as mentioned in the post above), turn on the ice maker, and move the control arm to the down position. You'll hear a little pump working as it tries to draw water from your line into the ice maker.
You'll probably want to throw out the first three or four batches of cubes. It'll take at least that long to get the plastic taste out of them from the water line. Ask me how I know!
If you don't have the owner's manual for your fridge, you can likely download it from the manufacturer's website. The model number for your fridge in normally found on a sticker inside the door of the non-freezer portion of your fridge.
HTH.
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Jeff & Laurie -- Full timing in Rockport, Texas
Auggie (our beer-loving English Cocker Spaniel)
Angus (55 pounds of attitude in a 5 pound chihuahua body)
Our home base -- 2018 Grand Design Solitude 375RES -- The "Uno Mas!"
The mobile office -- 2016 Crossroads Hill Country HCT26RB -- The "Poquito Mas!"
Gone but not forgotten: 2015 Heartland Landmark 365 Key West (lost to Hurricane Harvey)