2Drain the fruit cocktail, pineapple and mandarin oranges, reserving 3 cups of the juice. Set the fruit aside, then pour the juice into a 4-quart serving bowl. Add the pudding mix, and stir or whisk until the mixture is smooth. Stir in the sour cream. Add the whipped topping, and stir again until the mixture is smooth. Fold in the fruit.
3Chill then serve the salad
4Chill the ambrosia for several hours (at least four to six, and ideally overnight). If desired, top the salad with chopped pecans just before serving.