Replacing switch plates without a colour guide .

[Fleeting]

Put some in focus pics up expanding those makes it worse.

 

[Chewbacca]

Hi .
This is the light switch for my landing light . It had no butt connector ..the reason why the brown is hanging on is I realized I'd removed the other wires before photographing it.
There another brown .
And then BLK blue and grey all sleeved by brown

anything sleeved brown is usally a 'line' or live in old terms. If you have only undone one screw terminal, logic says they all go back in that terminal, unless there was any unused. Have to say that would be rather unusual as it sounds like a modifed standard two way. I would have expected the 2 core cable connected to L1 and L2, and the 3 core, brown in common, blue and grey in L1 and L2 - doesn't usually matter which one. It's possible the terminal you havn't undone was actually loose and allowed the cables to just fall out.

as for test gear, it would be good if you are planning a career in electrics, to buy a set of Voltage probes, they are very useful for such problems. You should be looking for a live supply on the 2 core, which would be the switch line to the light, leccy in on one core, leccy out on the other. To test for that you will need to renergise the cct, so be careful. Whilst live, check the 3 core cable cores for anything live, they should be all dead. You can confirm that with the volt probes. If all dead, then these are two way switching cores, one common and 2 'strappers' as they are known. Turn leccy off again, twist together the 3 cores and check at the other light switch for continuity between the cores NB turn off upstairs and downstairs MCBs whilst doing that. This test will confirm the 3 core is being used for two way switching.

 

[Dusty'sDwarf]

anything sleeved brown is usally a 'line' or live in old terms. If you have only undone one screw terminal, logic says they all go back in that terminal, unless there was any unused. Have to say that would be rather unusual as it sounds like a modifed standard two way. I would have expected the 2 core cable connected to L1 and L2, and the 3 core, brown in common, blue and grey in L1 and L2 - doesn't usually matter which one. It's possible the terminal you havn't undone was actually loose and allowed the cables to just fall out.

as for test gear, it would be good if you are planning a career in electrics, to buy a set of Voltage probes, they are very useful for such problems. You should be looking for a live supply on the 2 core, which would be the switch line to the light, leccy in on one core, leccy out on the other. To test for that you will need to renergise the cct, so be careful. Whilst live, check the 3 core cable cores for anything live, they should be all dead. You can confirm that with the volt probes. If all dead, then these are two way switching cores, one common and 2 'strappers' as they are known. Turn leccy off again, twist together the 3 cores and check at the other light switch for continuity between the cores NB turn off upstairs and downstairs MCBs whilst doing that. This test will confirm the 3 core is being used for two way switching.

Thanks Chewbacca .I'm popping down to the store to grab a cheap multimeter , as I was only upgrading switches I thought it would be a simple copy and paste job , but because the new component is labelled differently nothings switching on.Thanks you've made it understandable .
I figure to do this successfully
I need to have the right equipment.

 

[Fleeting]

A cheap multimeter is not the right equipment if you intent to test live conductors.

 

[Dusty'sDwarf]

I've checked there are no two core cables . The earth's are tucked to the side into screw connectors .
I have 2 three core cables . The one coming in from the top is sleeved neutral , a brown then E
The one coming in from the bottom left which is probably under the floorboards is brown- Sleeved Grey and brown -Sleeved Black .To the untrained eye it looks like alot of brown wires .
That should clarify the blurry photo

anything sleeved brown is usally a 'line' or live in old terms. If you have only undone one screw terminal, logic says they all go back in that terminal, unless there was any unused. Have to say that would be rather unusual as it sounds like a modifed standard two way. I would have expected the 2 core cable connected to L1 and L2, and the 3 core, brown in common, blue and grey in L1 and L2 - doesn't usually matter which one. It's possible the terminal you havn't undone was actually loose and allowed the cables to just fall out.

as for test gear, it would be good if you are planning a career in electrics, to buy a set of Voltage probes, they are very useful for such problems. You should be looking for a live supply on the 2 core, which would be the switch line to the light, leccy in on one core, leccy out on the other. To test for that you will need to renergise the cct, so be careful. Whilst live, check the 3 core cable cores for anything live, they should be all dead. You can confirm that with the volt probes. If all dead, then these are two way switching cores, one common and 2 'strappers' as they are known. Turn leccy off again, twist together the 3 cores and check at the other light switch for continuity between the cores NB turn off upstairs and downstairs MCBs whilst doing that. This test will confirm the 3 core is being used for two way switching.....

 

[poni]

I've checked there are no two core cables .

the cable most used in domestic circuits would be Twin and earth ( brown, blue and bare )or three core and earth (brown, black, grey and bare) some times single core and earth( this could brown or blue with a bare core)
from your blurry photos it looks like you have one twin and earth and one three core and earth, with the blue of the twin sleeved with brown and the black and grey from the three core both sleeved brown

so the twin brown and the blue sleeved brown, should be the switched pair (one permeant live and one switched live )
the three core could be the strappers for the two way switching, 2 of them would be live all the time when switched,

so the two way switch has 3 terminals they should have the same cores in each of the switches,( it does not matter as long as all the L1's have the same colour cores in each, and the same with L2 and common ,
the twin cable has to double up in two terminals, but from you photos its hard to see the numbers on the switches, so I cant tell you which terminals you should put them in , there is no standard switch markings , all makers have there own,

all the bare cores must be sleeved with green and yellow sleeving, and joined together and linked the switch plate if it is metal

A cheap multimeter is not the right equipment if you intent to test live conductors.

most of all remember the above, its your life after all,

 

[SPECIAL LOCATION]

Only sort of skip-read previous post...
so I may have missed an important bit of info...

BUT.. a common difficulty for DIY's with light switch related problems...
is that there is NO industry standard label / designation for light switch terminals...

e.g. On some 2-way switches terminals are labelled 'C', 'L1', and 'L2',
where the electrical connections are swapped between 'C' to 'L1' and 'C' to 'L2'.

However on other manufactures they are labelled... 'L1', 'L2' and 'L3',
where the electrical connections are swapped between 'L1' to 'L2' and 'L1' to 'L3'.

So if you just swap 'L1's' and 'L2's' then join the 'L3' and 'C' it will NOT work correctly!!!

Also there are NO set rules about which cable colours are used for each terminal..
So the actual colours used, Brown/Black/Grey.. (previously Red/Yellow/.Blue on older wiring).. will be down to the person designing / installing the work.

Personally I tend to use Brown (or Red) for 'C' / 'L1'
Black (or Yellow) for 'L1' / 'L2'
Grey (or blue) for 'L2' / 'L3'

Depending upon age or wiring, type of switch.

 

[binky]

Ok a picture speaks a thousand words, as somebody once said, https://images.app.goo.gl/u9KuMSw5GWYQjS7T8

 

[poni]

Only sort of skip-read previous post...
so I may have missed an important bit of info...

BUT.. a common difficulty for DIY's with light switch related problems...
is that there is NO industry standard label / designation for light switch terminals...

e.g. On some 2-way switches terminals are labelled 'C', 'L1', and 'L2',
where the electrical connections are swapped between 'C' to 'L1' and 'C' to 'L2'.

However on other manufactures they are labelled... 'L1', 'L2' and 'L3',
where the electrical connections are swapped between 'L1' to 'L2' and 'L1' to 'L3'.

So if you just swap 'L1's' and 'L2's' then join the 'L3' and 'C' it will NOT work correctly!!!

Also there are NO set rules about which cable colours are used for each terminal..
So the actual colours used, Brown/Black/Grey.. (previously Red/Yellow/.Blue on older wiring).. will be down to the person designing / installing the work.

Personally I tend to use Brown (or Red) for 'C' / 'L1'
Black (or Yellow) for 'L1' / 'L2'
Grey (or blue) for 'L2' / 'L3'

Depending upon age or wiring, type of switch.

rightly or wrongly, I assumed both switches are new switches and are the same make,
I did say that all accessory makers have there own marking system
Special Location, you explained better than I could have , ,

 

[Dusty'sDwarf]

Only sort of skip-read previous post...
so I may have missed an important bit of info...

BUT.. a common difficulty for DIY's with light switch related problems...
is that there is NO industry standard label / designation for light switch terminals...

e.g. On some 2-way switches terminals are labelled 'C', 'L1', and 'L2',
where the electrical connections are swapped between 'C' to 'L1' and 'C' to 'L2'.

However on other manufactures they are labelled... 'L1', 'L2' and 'L3',
where the electrical connections are swapped between 'L1' to 'L2' and 'L1' to 'L3'.

So if you just swap 'L1's' and 'L2's' then join the 'L3' and 'C' it will NOT work correctly!!!

Also there are NO set rules about which cable colours are used for each terminal..
So the actual colours used, Brown/Black/Grey.. (previously Red/Yellow/.Blue on older wiring).. will be down to the person designing / installing the work.

Personally I tend to use Brown (or Red) for 'C' / 'L1'
Black (or Yellow) for 'L1' / 'L2'
Grey (or blue) for 'L2' / 'L3'

Depending upon age or wiring, type of switch.

Only sort of skip-read previous post...
so I may have missed an important bit of info...

BUT.. a common difficulty for DIY's with light switch related problems...
is that there is NO industry standard label / designation for light switch terminals...

e.g. On some 2-way switches terminals are labelled 'C', 'L1', and 'L2',
where the electrical connections are swapped between 'C' to 'L1' and 'C' to 'L2'.

However on other manufactures they are labelled... 'L1', 'L2' and 'L3',
where the electrical connections are swapped between 'L1' to 'L2' and 'L1' to 'L3'.

So if you just swap 'L1's' and 'L2's' then join the 'L3' and 'C' it will NOT work correctly!!!

Also there are NO set rules about which cable colours are used for each terminal..
So the actual colours used, Brown/Black/Grey.. (previously Red/Yellow/.Blue on older wiring).. will be down to the person designing / installing the work.

Personally I tend to use Brown (or Red) for 'C' / 'L1'
Black (or Yellow) for 'L1' / 'L2'
Grey (or blue) for 'L2' / 'L3'

Depending upon age or wiring, type of switch.

Great advice. Thanks