Correct me if I'm wrong, but it looks as if your fuchsia is sitting in a relatively small pot sitting inside a larger one, not actually planted into it. The usual cause of yellowing leaves in pots is insufficient water/constriction at the root, so if I am correct, decant your fuchsia and repot with fresh potting soil into something larger which has drainage holes, and water in well. If the rootball is solid with roots coiled round and round, tease them out a little; unfortunately,its a bit late in the growing season to rake the rootball to loosen it up and cut back the topgrowth by a third, which is what I'd recommend to enourage new growth were it currently May or early June. Fuchsias actually prefer partial shade to full sunlight and they do not like to dry out, preferring moist but well drained soil conditions - if the plant is potbound, the soil to root ratio is wrong and its difficult for the plant to hang on to enough water to remain healthy, even if you water daily.