Found the following, don't know if the recipe is any good... http://www.recipelink.com/mf/20/2596
The following text is from the URL
There are several ways to make sugar free jams. You may purchase a pectin designed for no sugar jams and follow the recipes. There are recipes that use a liquid sugar substitute. I just found this on the web:
1 cup unsweetend apple juice
1 cup sliced strawberries,fresh or frozen
1 1/2 T. cornstarch
Combine 1/2 the berries,apple juice and cornstarch in a blender.Pour into a saucepan and bring to a boil. Turn down on low and simmer until thick.Can be used as a sauce while hot or chill and use as a jam. Pectin can be used instead of the cornstarch which is what the store brands do.Also can substitute other fruit juices and fruit to make other flavors. I know when I purchase sugar free spreads, they use white grape juice, fruit,and pectin. I may give this method a try myself. I have also heard of recipes that use gelatin, but don't have one yet.