Toilet light fitting - help..!

[notadiyexpert]

I disconeted an old ceiling rose and found 3 red wires and 3 black wires. No earth.
They are initally connected as -
3 red wires together in one conection.
2 black wires together in one conection.
1 black wire in a conection on its own.

I contected all 3 red wires together.
I have conected 2 black wires together (seperate from the new light fitting) and the remaining black wire to the new fitting.

As all the downstairs lights are all on the same circut through trial and error I discovered that when I conected all the black wires together the new light was on constantly, flicking the switch blew the fuse.

I have contected 2 black wires together and the downstairs light now all work except the for the new light, which I have contected the remaining black wire to.

Hope I have managed to explain, please help..!!!

 

[JohnD]

It is quite likely that the "black on its own" is the switched live (and ought to be marked with red sleeving or tape). In that case, connecting the bulb between the "switched live" and the "two blacks in one terminal" will make your light work controlled by the switch.

If you splash out £9 on a multimeter you can test across the wires to see what they do.

 

[sm1thson]

hi, theres some pictures that explain it here as for the no earth, i take it your light isnt metal if it is that is very dangerous (and the same goes for the other light fittings in your house presuming the no earth problem persists through all the house lighting).

 

[JohnD]

that's a good link, sm1thson. The pic is the very one

In this picture the blue wire with the short red sleeve on it is the switched live.

 

[notadiyexpert]

Thanks John D.

Maybe I'm not understanding what you mean, but if I'm right in what you are saying then you mean I should connect the 'lone' black wire to the other 2 black wires?
I did try this and the light was on constantly and blew the fuse when I flicked the switch.

 

[JohnD]

Nonononononononononononononononono.

The single black wire is a live/phase/line supply. Treat it as if it was red because (when the switch is "on" it is live. That is why it ought to be marked with red tape or sleeving.

Do not connect it to anything except the supply to the lamp.

The neutral supply to the lamp comes from the other black wires which are all connected together.

 

[notadiyexpert]

Thanks again JohnD.

Really don't want to appear thick here... probably am tho...

If I connect the 'lone' black wire to the live conection, what do I do with the other 3 red wires? And do I leave the other 2 black wires connected together (but seperate from the new light fitting?)

thanks,

 

[JohnD]

...I connect the 'lone' black wire to the live conection...

If you mean the "L" terminal on the lampholder, or light fitting, yes, after putting some red tape or sleeving on it to identify it as the switched live.

what do I do with the other 3 red wires?

You leave them, connected to each other, in a terminal, but NOT connected to the lampholder or to anything else.

And do I leave the other 2 black wires connected together (but seperate from the new light fitting?)

You leave them, connected to each other, in a terminal, and also to the "N" terminal of your lampholder