Thank you I will try that.
I was thinking of soemthing earlier.
The switch is a double switch (there are two switches together) The other switch controls a different light. Are these two separate or could wiring the two lives the wrong way round in the ceiling rose affect things.
I...
One wire is grey 1 or 1.5 mm2 whilst the other two are white 2.5 mm2.
I really can't see that I have confused the switch wire. Could there be any other explanations.
Also, there is very little wattage on this circuit so I can't be overloading it.
I have been having a really bad time changing a florescent light fitting to a four bulb light fitting.
I disconnected the strip light and there were three wires - two for the circuit and one for the switch. I then tried to connect all three wires into the new light fitting, 3 black wires...