I have tried to replace a light fitting today. It seemed simple, although I cannot get the light switch to switch the light on and off. I have red, black & earth coming from the light switch and the same coming from either the consumer unit or another light fitting. (Just the two sets of wires!) Any suggestions. PS. Have tried connecting blacks to connectors either side of light fitting wires as was before and connected the two reds to the middle block of three connectors and earth to the earth block.