Have you looked at the cord switch? I have known these to break inside. Usually the trip will go if the switch is shorted out but if it is just broken, then you will get no lights, now power to the shower and obviously the shower will not work. Switch off at the mains, remove the switch and get it tested. It will either work or not. The switch should be a double pole, meaning the circuit to both wires is cut when switched off. Often because the wires are so thick and do not fit in the space provided very well, the switch can be under pressure and this will break them also.
John Holden, November 2006
