The wires to the dimmer and those that connect dircty to them are the same size. However the wires in the ceiling vs. the wires that go to the switch appear to of different size, slightly. The wires in the ceiling are probably original (cloth insulated, can't really tell what color the wires are by looking at them). Whereas the wires to the switch are new sheathed electrical cable. Could this be causing the problem? And I will consider lowering the wattage.