I don't know if it is the "proper" way but it is the way I do it...
1. Turn on the fridge.
2. Open low point drains and purge water from the system (ours has a low point drain right below the fridge.
3. Open freezer and remove the cover to the ice maker - two test points using a piece of electrical wire to jump causes the valve to open and close.
4. Hook air line to the city water connection (~5-8 lbs)
5. Re-install the low point drains
6. Cycle the ice maker a couple of times to ensure only air comes out
7. Wipe out the ice maker with paper towel to ensure it is dry
Walter & Donna
2011 CC LB RAM 3500 CTD 6.7L DRW
2013 Cedar Creek 38FL
2014 Days Camping: 35