rewiring the wires in a light fitting

[lexi123]

I have just taken off a very old light fitting in a bathroom and it has crumbled this meant that the wires came loose before I had a chance to look where they went. The ceiling rose is a junction as there are several wires coming from it. Can anyone help me put them in the correct place. I have chosen a double insulated fitting as there's no earth so only have a brown and blue wire to attach. I have the old wiring colours and know it's black to blue and red to brown. All in all there are 4 red wires and 4 balck wires in pairs bound in grey insulation. So I am thinking they're coming from the previous light, the light switch and this new fitting etc. I have nothing on the wires so it's a bit of a hazard so would really appreciate any immediate help.

 

[wingcoax]

Firstly SWITCH OFF!! Then if you have a continuity tester with the switch on test between red and black until you get a beep(or whatever) then test the same wires with the switch off, these are your switch wires. put the other red wires into the centre terminals of the new rose and the other blacks into the end with three connections, the switch wires go red into centre connections and black into end with two connections, this wire should be marked with a red/brown sleeve,your light can be connected brown to the wire with sleeve and blue to the terminals with the black wires.

 

[lexi123]

Sounds a bit complicated. there are only two terminals in the new fitting and where are the three connections you mention?
Eitherway think I ought to ask for help from someone who can see what they're doing.Thanks for the time and advce.

 

[ColJack]

a picture paints a thousand words..

post a photo of the wires in the ceiling and we'll see what we can do..

 

[Taylortwocities]

You'll need more tahn two terminals as you have to connect the live loop in there too.

Here's how it's wired: http://www.diynot.com/wiki/electrics:lighting:lighting_circuit_layouts

 

[lexi123]

Thanks for all this. I'll post a picture of it tomorrow it's a bit dark in there at the moment! please see what you think.
Thanks

 

[lexi123]

I have actually posted this ame question on another forum but there's no one answering there so have brought it here.
Here's what I think is going on;
Altogether there are four reds and four blacks. I have been able to identify my switch wires by simply pulling on the flex when I undid the light switch fitting.
There are two red wires are wound together I have now returned them to the block with the a seperate single red wire at the other side, the bedroom lights that weren't working are now okay, so this is obviously supply in and supply out to the other rooms and therefore are not connected to the new lamp at all?.

There are three black wires which are all twisted together therefore I believe these should go to the neutral blue in the new light fitting?.That then leaves us with one black wire which should be the switch live and should go to the brown live in the new light fitting but I am still left with one red, now if I have this right this red belongs with the other reds and does not need to enter the new light fitting at all?, but should it go with the reds which are going in a pair into the block or with the single one on the other side?

If this isn't right I'll get someone in but I think I have it okay, just need verification!

 

[wingcoax]

If the remaining red is a switch wire then connect to the two reds and you should be ok.

 

[333rocky333]

There are two red wires are wound together I have now returned them to the block with the a seperate single red wire at the other side,

I am still left with one red, now if I have this right this red belongs with the other reds and does not need to enter the new light fitting at all?, but should it go with the reds which are going in a pair into the block or with the single one on the other side

What is this "BLOCK" is it a connecter block, if so it is joining all 3 reds anyway, irrespective of what side the wires are in.
Regarding the spare red if you connect it in that block, it will permanently supply whatever is on the other end.
I take it the corresponding black with that red is with the black neutrals at present
Has there ever been a second light/ wall light/fan in the room, that may be the other end of the cable.

 

[lexi123]

What is this "BLOCK" is it a connecter block, if so it is joining all 3 reds anyway, irrespective of what side the wires are in.
Regarding the spare red if you connect it in that block, it will permanently supply whatever is on the other end.
I take it the corresponding black with that red is with the black neutrals at present
Has there ever been a second light/ wall light/fan in the room, that may be the other end of the cable.

Yes the block is a connector.
So the spare red then I will put with these other reds.
But the corresponding black I presumed was the switch live as mentioned slsewhere. So I presumed it would therefore go to the brown of the new lamp.
In other words no the spare red is not with the other blacks. It is with the currently unconnected red.
There appears to have been an additional light to the loft from this rose which accounts for the the four blacks.

From what you say, is it then possible that this spare black is a neutral. I thought that the black to the switch was actually live and should have a red sleeve?

I'd like that confirmed prior to connecting it all up.Thanks

 

[ericmark]

In the for Reference section there are many pictures like this one

which may guide you.

However do be aware the wiring you have was removed from the recommended method of wiring in around 1966 and from that date all lighting has been supplied with an earth.

Although the Electrical Safety Council in their best practice guide No 1 do suggest signs and using RCD protection it is never the less a potential danger especially in a bathroom.

There are many ways to reduce the dangers from separated extra low voltage to using a RCD switched fuse spur from the power circuit.

I would consider some professional help. One is a long time dead and in a bathroom mistakes can be deadly.

 

[333rocky333]

yes you are right the switch live is usually black.
Usually the corresponding red with it will join to the other reds.

All reds usually go together,exception being a red to a second light or similar, which needs switching on/off.

I thought you pulled and established the black from the switch and the corresponding red with it ,was one of the three already in the block.

I thought It was the extra red left over you was querying.

 

[lexi123]

The red in question was indeed with the black which I established were the two wires coming from the Switch. This red is not currently with the other reds because until now I wasn't entirely sure where it went.
It is the fourth red and is not one of the three that I have already put into the block.
To clarify, at present there are three reds in a connecting block. there are three blacks together but at present are not connected to anything.
Then there are the two wires red/black which were the ones I found were connceted to the switch and again these are not currently attached to anything.
So am I right in the 3 blacks go to the blue and the single red goes to the other reds and the single black goes to the brown.

 

[333rocky333]

So am I right in the 3 blacks go to the blue and the single red goes to the other reds and the single black goes to the brown.

Sounds right yes.
Red from switch with the other reds
black from switch will on its own go to light feed brown
The other blacks join to blue.

Normally You only have 3 reds
Live in,Live out and Live to switch.

2 blacks
N in and N out join to N blue to light

1 Black return from switch, join to brown live to light

Your extra red and black, as you say is a loft light.
If there is a switch in the loft, then that red will also go with the other 3 reds and that black with the other two blacks
Which I think you had already done.

 

[lexi123]

one last thing on this, is the black switch wire always a live wire and short of having a multimeter how can I be sure. Is there any chance that the black wire could be as normal and a neutral wire. If there's any chance that the black could be a neutral and not a live then I'll go and get a multimeter. Thanks to all.

Since posting this a little light went on in my head and I realised the black wire has to be live to take the live back to the light fitting. So as long as I am certain that the black wire in question is indeed live I am okay. It took a while but the penny finally dropped!!!