I have just replaced 2 old wall lights with more attractive lights. They both come on together from the same switch (a 2 gang, 1 way for the wall lights, 2 way for the stair lights) and each had an independent push switch also, but no more.
The problem is that the first wall light will come on, the second now will not.
The first light has the conventional earth, live and neutral wires, and that's it.
The second light has an earth and 2 sets of twin wires, all of the same nondescript colour. They had been taped together and having removed the tapes I was distracted by the phone (as ever) and didn't note which was taped to which.
I have assumed that logically the two live wires should be taped together, and similarly the neutral wires. (the fuse box tripping told me which combination seemed to be the correct one!) The result however is that no light comes on.
When I tested the live lamp terminal where the bulb sits, the terminal sparked aggresively. Is this normal? I had thought that only the screwdriver should have glowed?
I would guess same as with ceiling rose supply in, supply out, connection to switch. In which case to connect all like colours together will result in a short circuit. So cables will now require testing to find which is which.
In the past I have tried to instruct how but in the main DIY guys have been unable to follow my instructions so sorry it's case of get an electrician.
Don't worry about me, I'm a fast (and cautious) learner!
To recap: In the first light, which comes on ok, there is a Live in and a Live out, there is also a Neutral in and a Neutral out, and of course an Earth. At the switch, which is a 2 gang, single and two way, the Neutral goes to L 1 and the Live goes to L 2 at the top, for the single, while for the two way, it's Live to both Commons and Neutral to L 2 at the bottom.
My problem is that at the second light there is an earth, and two parallel twin flexes sticking out, which are causing me the problem. Why on earth would flex be used when the twin and earth cable was clearly on its way anyway from the first light? Maybe it was the original wiring which was easier to attach to a junction box? I'm trying to avoid (though I may have to) having to lift the floorboards upstairs to find the junction box because I will have to first move to somewhere a massive chest of doors and a huge double wardrobe!
It is very unlikely you have a Neutral going to L1 with a Line going to L2. It is far more likely that you have a switched line and feed line. One using a red wire the other using a black wire. Because a wire is black or modern colours blue with out a sleeve does not mean it's a neutral.
Clearly however the wires are un-marked and other than tracing with a black one end being likely the same as the black other end of cable the colours of the wires tells one very little.
However I have been banned from this site once for trying to lead people along the testing procedure.