Allow the ham to stand at room temperature for 30 minutes before grilling.
Prepare the grill for indirect cooking over medium–low heat (about 180ºC).
Score the ham in a large criss-cross pattern about 2.5 centimetres apart and 1 centimetre deep on all sides, except the cut side. Place the ham, cut-side down, in a grill-proof roasting pan and pour in the apple juice. Loosely cover the ham only with aluminum foil. Brush the cooking grates clean. Grill the ham over indirect medium–low heat, with the lid closed, until an instant-read thermometer inserted in the thickest part of the ham (not touching the bone) reaches 48°C, 2 to 2½ hours. Meanwhile, prepare the sweet potatoes.
Bring a large saucepan of lightly salted water to a boil over high heat. Add the sweet potatoes and cook until a small, sharp knife inserted into the centre of the potatoes meets with just a little resistance, 8 to 10 minutes. Drain and rinse under cold running water. Let cool completely, at least 1 hour.
In a small saucepan over medium–low heat on the stove, combine the glaze ingredients and heat until the jelly is melted, whisking occasionally. Set aside.
Related Grill Skills
When the internal temperature of the ham reaches 48°C, remove the foil. Brush the ham with half of the glaze and continue cooking for 15 minutes. Then brush with the remaining glaze and cook until the glaze is set and an instant-read thermometer inserted in the thickest part of the ham (not touching the bone) reaches 54°C, about 15 minutes more. Remove the roasting pan with the ham from the grill and take the ham out of the pan. Set the pan with the cooking liquid aside. Cover the ham loosely with foil to keep warm.
Brush the sweet potato wedges with the oil and season evenly with the salt and pepper. Grill the sweet potatoes over direct heat, with the lid closed, until they are nicely marked and just tender when pierced with the tip of a small, sharp knife, 10 to 15 minutes, turning occasionally. When fully cooked, add the sweet potatoes to the roasting pan and toss with the reserved cooking liquid. Using a slotted spoon, transfer the sweet potatoes to a serving bowl.
Cut the ham into slices and spoon as much of the remaining cooking liquid as you like over the slices. Serve warm with the sweet potatoes.