Arrange ham in slow cooker broad side down. (See below) Pour orange juice and sprinkle the ground cloves over ham. Spoon on the brown sugar doing your best to press as much onto the outside of the ham.
Put lid on slow cooker and cook on low for 4-6 hours, or high for 2-3 hours. Note that hams come pre-cooked, so really you're only heating it up and melding the flavors. There's no need to cook it all day long and you only run the risk of drying it out!
Once you're ready to serve your ham, you can ladle and strain out 1 cup of the liquid, then microwave it on high for 1 minute to thicken it up. Slice ham, then drizzle glaze on top.