just fitted a 3 gang switch but I cannot get all of the lights working at the same time as the way it is wired is different to the old switch therefore the wires need the order changing. I fitted one downstairs and that is fine.

Am I safe testing which wires are live by using a multimeter?

Yeah, but be aware that a multimeter might show an induced/inducted voltage if its digital type..

You also shouldnt have a neutral in the switch so may have to test between live and earth which may trip an rcd.. i would try swapping an L1 and common first then swap back and maybe l2 and common if it doesnt work.

Then next time cut the wires to the switch, so you know where they go when you make a balls up!!! ;)

Yeah, but be aware that a multimeter might show an induced/inducted voltage if its digital type..

You also shouldnt have a neutral in the switch so may have to test between live and earth which may trip an rcd.. i would try swapping an L1 and common first then swap back and maybe l2 and common if it doesnt work.

Then next time cut the wires to the switch, so you know where they go when you make a balls up!!! ;)

Isn't that what digital cameras were invented for? :D

Alcazar, (who still uses a neon mains tester :eek:) Well it WILL finnd a live;) )

Then next time cut the wires to the switch, so you know where they go when you make a balls up!!! ;)


fookin genius idea! :lol1:

Fed up of switching wires, there are about 8 reds, 2 yellows, 2 earths, and 2 neutrals that are safely blocked off out of the way!

IMO the best thing for testing live wires is one of these (http://rswww.com/cgi-bin/bv/rswww/searchBrowseAction.do?D=drummond%20test%20lamp&Ntt=drummond%20test%20lamp&Nr=avl%3auk&Ntk=I18NAll&N=0&Nty=1&name=SiteStandard&forwardingPage=line&R=4812116&callingPage=/jsp/search/search.jsp&BV_SessionID=@@@@1930167714.1160759546@@@@&BV_EngineID=cccladdjdghhlkdcefeceefdffhdgmh.0&cacheID=ukie), not cheap but they don't lie unlike some neon & electronic testers

Tim

sounds to me like you have 2 x 2 way lighting circuits, and a 1 way lighting circuit.

Does that sound about right? If so, I can easily tell you how to connect the wires:thumb:

you mean 8 reds, 2 yellow, and two BLUE cores?

that probably means that there are two 2 way circuits at the switch in question. Each 2 way will use one yellow, one blue, and could also use a red depending on how it's wired, so thats maybe 6 dealt with.

always work with the power off...

The only way to really find out is to connect every core into a strip of connector block.

I would do the same at the cables at the other end of the 2 way circuits.

Then stick the juice on and establish which cores are live, make a note of this.


power off....

i would then eliminate all the wires in the 2 way circuits by belling the cores to earth...i.e, go to the other end of the 2 way and connect one of the 3 cores to earth red,yell or blue.
then go to your main block and test all cores to earth, one will be down. if the cable still has some insulation showing then this will eliminate the other 2 cores in the 2 way circuit.

put sone tape round these so as to eliminate them...

I would then connect a small piece of cable to the KNOWN live core, and connect the end to the remaining reds to see which lights come on...power off while you are doing the cable swaps.


Note: if you do have black cores at the switch then this changes things somewhat, but makes the prescence of yellows a bit odd :wonder:

if you can still see the grey insulation, then tell us what cores are coming out of each cable, should make it easier.

To me it sounds like 2 x 3 Cores, and 3 x twin reds (Ignoring the Earths).
Is that right?
If so each 2 way would use a 3 core and a twin, which would leave you with a twin red left unused. Which I suspect would be a 1 way.

fook now I am confused.
The upstairs 3 way controls the bathroom light, the bathroom extractor fan, and the upper landing light
The downstairs 3 way controls the bottom landing light, upper landing light and the front room. When I changed the downstairs one, everything worked as it should so I am confident that is okay.

With the upstairs there were 2 x twin red (by that I imagine you mean 2 reds sort of twisted together?) 2 x single reds, 2 yellows, 1 blue and a few black and an additional blue which are not connected to anything (they are in a plastic insulating block). There was also 1 single strand of red cable that was connected from one of the yellow feeds to one of the red feeds (cannot remember if it was connected to a twin red or single red or blue!!!)

Basically the switch on the back (where the wires go) has on 1 end an L and on the opposite ends an L1 and L2, this is times 3 (for each switch) Now the fan did previously come on automatically when the bathroom light was switched on so I think the single strand (one end connected to yellow L terminal) was I think connected to the bathroom switch so when that was on, power was supplied to the fan terminal if you see what I mean (but saying that if yellow is live then I should connect to the L1 or L2 switch shouldnt I?)

When I put everything back as it was dark (hard working in torchlight) the back bedroom light wouldnt come on unless I switched on one of the switches on the top landing

Will have a good look tomorrow when I get daylight but any suggestions in the mean time?
I have now got a multimeter so I take it I would connect one end to the red wires (individually) and the other end to the black wires that arent connected or should it be the yellow wires?

according to the multimeter there is only 1 live wire in there?

That's not unusual.

what colour cores are coming out of what cables?

i.e,

cable #1 / 1x red,1xblack,1x earth
cable #2 / 1x red,1xyellow,1x blue,1x earth

get that info, and point out which cable contains the live you have found.



Do ALL testing to earth.

right checked the switch downstairs again, the switch that controls the upper landing from downstairs has a blue wire connected to it, so I guess that the blue wire upstairs is for this switch. I have the bathroom light now working but only have a single wire coming out of L1 whereas on the old switch it was a twin. I know which red to connect so I can switch the landing on upstairs so now I just need it to work in conjunction with the switch downstairs. Would I be right in using the blue wire in L2?

right, there are 4 cables
Cable 1 has 1 x red (this is live) 1 X black, 1 x earth
Cable 2 has 2 x red, 1 blue (isolated with some blacks), 2 x earth, 1 x yellow
Cable 3 has 2 x red, 1 x yellow, 1 x earth, 1 x black, 1 x blue (connected to switch think its part of the circuit for the downstairs switch)
Cable 4 has 1 x red, 1 x black, 1 x earth

1 and 4 make sense, but I've never seen colour/core combo's like in cables 2&3. :wonder:

right given up, gonna call somebody in.
I have managed to get the bathroom light working along with the extractor fan which is how it worked previously, I have also managed to get the landing light working, but only from the upstairs switch, and the middle switch for the extractor fan itself I cannot get going. Its as though I am missing a live somewhere.

can you not just loop the live you know to other commons on the other gangs?

1 is already looped for the landing light.

It has definately got something to do with the circuit from the switch downstairs, but I know that is definately right as I tested it after I changed that one and everything worked as it should.

Originally on the upstairs, the looped live went to the extractor fan, so that when the bathroom light went on so did the fan.

Anyway gonna get a pro in as I have a bathroom suite to fit. ahhh the joys of selling a house!!

Cheers for your help and pointers anyway. Wouldnt have got any lights working without your info

1 and 4 make sense, but I've never seen colour/core combo's like in cables 2&3. :wonder:

Absolutely agree. Just have another good look at the wiring. Especially which cores are in which cable.
You will basically have a choice of 3 cables

Standard Twin and earth - Contains 1 red, 1 black, and 1 earth
Twin Red - Contains 2 reds, and one earth
3 core and earth - Contains 1 red, one yellow, one blue, and one earth.

There's a very slim possibility you'll have singles and earth, but I doubt it.

Perhaps take a couple of piccies too:thumb:

Another thing that will help.
You mentioned the upper landing light is 2 wayed with downstairs.
Look in the switch downstairs that controls that light. There will be 3 terminals. Common, L1, and L2.
Do L1 and L2 have 2 cores in each, or just the one?

I'm confident we can sort this, all we need is plenty of info:wonder:

will try to take some later, but it may be at weekend due to light etc. Will post back

back again

Cable one has 1 x red, 1 x blue, 1 x yellow which is sleeved red, 1 earth

Cable 2 has 1 x red (which is perm live), 1 x black, 1 x earth

Cable 3 has 1 x red, 1 x black, 1 x earth

All of the above black and blue wires terminate in a plastic connector

Cable 4 has 1 x blue, 1 x yellow, 1 x red, 1 earth. Both the blue and yellow are sleeved with red

Cables 5 and 6 have 1 x red, 1 x black, 1 x earth. Again the black terminates in the plastic connector

There is also a loop wire as well

Does this make more sense?

John@tuner is the man for this, I'm not a real sparkie, I do industrial ;)

John@tuner is the man for this, I'm not a real sparkie, I do industrial ;)

okay cheers Chip :thumb:

OK, working on this now. When you say loop wire, what do you mean? Is it a short piece of cable that connects 2 of the terminals in the switch?

Right, Here's what I think you have there

The 3 core that has the yellow sleeved goes to the fan (Hopefully via a fan isolator)
The 3 core that has both blue and yellow sleeved up goes to the other switch downstairs.
The twin with the permanently live red is obviously the feed and neutral IN

Now then, the other 3 twins I think do the following:-

Feed and neutral OUT
Switch wire and Neutral to the bathroom light
Switch wire and Neutral to the top landing light

Finding out which is which needs a little bit of testing, so find yourself a multimeter or continuity tester.

Essentially, you're aiming for something like this.

http://www.jbec.co.uk/Private/Switching-Diagram-1.jpg

Oh, and even though I've shown 4 reds in the 'C' terminal of the left switch, to give yourself more room you can easily put the 'feed out' red into either 'C' of the centre switch, or 'L1' of the right hand switch. It makes no odds as they're all linked anyway:thumb:

And I haven't shown any earths because they just all link together on the backbox, with a link to the switch plate too if it's metal.

has that helped? If you need any more info just let me know

Cheers John, I have wired it similar to that but you have one extra wire on the left switch going to the centre switch and then from the centr switch going to L1 on the right switch. The feed out was for the light in the back room so good news is all the lights are now working (the landing from downstairs as well as up switchable in both directions) just need to get the extractor one working now.

I connected the yellow wire with the red sleeve to L1 on switch one so that when the bathroom light is turned on the fan comes on but it doesnt work. For now the red wire for the extractor I have just connected to C on the centre switch, any ideas in getting the fan to work from switch 2 and also to work when switch one is on (bathroom light)?

The fan needs a permanent live on the red core, and a permanent neutral on the blue. Then the yellow core just tells the fan when the light is on.
Unfortunately there's no way to override the fan without the light on AND have the fan coming on with the light unless you use a relay.

If you want to go into relays, I can easily explain how to do that:)

The fan needs a permanent live on the red core, and a permanent neutral on the blue. Then the yellow core just tells the fan when the light is on.
Unfortunately there's no way to override the fan without the light on AND have the fan coming on with the light unless you use a relay.

If you want to go into relays, I can easily explain how to do that:)

but it used to be though that the fan came on when the bathroom light was on, or if you needed you could flick the middle switch and leave it on permanently

Hmmmmm, let me think about this. There may be a way by using the 2 way switch the opposite way around.:wonder:

Yes there is!! :idea:
Needs another drawing to make it clear though.
Bit busy today, but I can sort you one over the christmas break:thumb: