Help with light switch wiring

[EFLImpudence]

Ok, that's better.



Also, do you realise that the two switches are not TOP and BOTTOM, but -

COM, L1 & L2 on LEFT and COM,L1 & L2 on RIGHT.

So, when you said:

If I bundle them all into the same switch (2 blues to L1, 2 brownto common) I get weird behaviour i

Were you in fact using the L1 of one switch and COM of the other.


If you were, then now put the thin wires in one switch COM & L1 and see what happens.

 

[Harry Bloomfield]

Thick Blue: 4.9V
Thick Brown: 4.9v

Thin T&E Blue: 3V

Those obviously silly values, are the result of using a very sensitive, high impedance meter which offers almost no loading to the wires you are testing. Those very low measured voltages, are a result of current induced onto them, from other live wiring.

Safe to assume you are measuring 0v on them. The ones where you show 252v, are actually live.

 

[UnusualCapybara]

Thanks a lot for giving the time on this, learning by the minute...

I've just wired up the switch ignoring the 3-core for a second. Therefore I have:

Left-Com - Thick T&E Brown + Thin T&E Brown
Left L1 - Thick T&E Blue + Thin T&E Blue

In this configuration I get the same behaviour - flicking the switch one way turns on the wall lantern but turns off the low lights, and the other way turns off the low lights and turns on the wall lantern. Neither will stay on at the same time, and one or the other is always on.

Multimeter readings are as expected - Both blue and brown cable groups showing live voltage with the switch in the 'on' position and only brown group showing live voltage with the switch in the 'off' position.

Maybe a silly question but could this be a wiring issue at the other end (i.e. in the low level light or the wall lantern where live and neutral are switched over?

 

[EFLImpudence]

Left-Com - Thick T&E Brown + Thin T&E Brown
Left L1 - Thick T&E Blue + Thin T&E Blue

Remove the thick wires and see what works.

 

[UnusualCapybara]

Remove the thick wires and see what works.

Wall lantern outside works normally controlled by the switch. Multimeter readings support it - live voltage on brown into com, live when switched on the blue.

 

[EFLImpudence]

Right, so that is presumably that switch and light working properly.

Moment.

 

[EFLImpudence]

According to previous posts, the 3core Brown and Grey were live.

Out of the remaining wires - Thick Brown, Thick Blue and 3 core Black - have you any idea where these go?

Do they go to the low lights.? Can you work out anything with the meter?


I am wary of suggesting anything which might not be wise.

 

[UnusualCapybara]

Ok I think I can answer to the identities of the cables...

- It seems by elimination that the thick brown/blue go to the low level lights although I'm confused as to why neither have voltage when standalone.
- The thin T&E pair is the constant/switched earth for the wall lantern outside the front door.
- The 3 core controls a light inside the porch (via the 2nd switch) which I think has a secondary switch further inside the house which might explain the 3 core? The connections for these are (which I'm now going to correctly refer to):

Right Com: Brown
Right L1: Grey
Right L2: Black

When disconnected, brown and grey have live voltage, black does not

 

[EFLImpudence]

I haven't much time, but -

- It seems by elimination that the thick brown/blue go to the low level lights although I'm confused as to why neither have voltage when standalone.
- The thin T&E pair is the constant/switched earth for the wall lantern outside the front door.

Are the thick Brown and Blue connected to low level lights Live and Neutral?


So, is it that you want lantern and low level lights to be all controlled by the left switch?

It must be because you write:

- The 3 core controls a light inside the porch (via the 2nd switch) which I think has a secondary switch further inside the house which might explain the 3 core? The connections for these are (which I'm now going to correctly refer to):

Right Com: Brown
Right L1: Grey
Right L2: Black

When disconnected, brown and grey have live voltage, black does not

It is a puzzle why two are live - especially as Brown would be thought to be live.

I cannot tell you to connect anything else. It might be wrong.

 

[SUNRAY]

Sorry missed this one - there is another cable, its a 3 core (black/grey/brown) which I *think* is connected to a secondary switch in the hallway. I took detailed notes and pictures of both switches before touching them so I've put everything back exactly as it was. The complete layout of the porch switch as I found it was:

Com (top): Fat brown + brown from thin T&E
L2 (top): Fat blue + blue from thin T&E
L1 (top): Empty
L2 (bottom): Black from 3 core
L1 (bottom): Grey from 3 core
Com (bottom): Brown from 3 core

what happens to the 3 core if you alter the position of the switch in the hallway?

Can you post those photos of all switches wiring, including the hallway.? Simply copy and past them into a reply.

 

[SUNRAY]

I'm throwing out thoughts here and making a guess we are here:

Bottom left being the porch light.
There is a small possibility the black wire is the neutral and not part of strappers.

 

[UnusualCapybara]

I've attached pictures of both here - the brighter one is the porch switch in question, the other one with more wires is the one inside the hallway of the house which also controls some wall lights in the hallway via the second switch.

Flicking the left switch in the hallway does the following (The wiring closest to the camera on the hallway switch is the one in question.)

1. Turns off the inside light inside the porch
2. At the porch switch the 3 core behaves in the following way:

- Brown loses voltage
- Black remains with no voltage
- Grey remains live

In the picture of the porch switch, the thicker T&E represents both the thick and thin ones, I just have them combined with a wago downstream to avoid constantly jamming them into the switch whilst figuring this out.

 

[SUNRAY]

I've attached pictures of both here - the brighter one is the porch switch in question, the other one with more wires is the one inside the hallway of the house which also controls some wall lights in the hallway via the second switch.

Flicking the left switch in the hallway does the following (The wiring closest to the camera on the hallway switch is the one in question.)

1. Turns off the inside light inside the porch
2. At the porch switch the 3 core behaves in the following way:

- Brown loses voltage
- Black remains with no voltage
- Grey remains live

In the picture of the porch switch, the thicker T&E represents both the thick and thin ones, I just have them combined with a wago downstream to avoid constantly jamming them into the switch whilst figuring this out.

There is obviously another accessory or junction box somewhere. Did you notice if the colour circled wires are in the same cable?

If not can you list by numbers which form cables?

Are 1 black and 7 blue in the same terminal (looks like B1)

Does the position of switch with brown, black, grey cable make any difference to the porch light? there are 4 combinations of the 2 switch positions: up up, up down, down down, down up.

 

[UnusualCapybara]

There is obviously another accessory or junction box somewhere. Did you notice if the colour circled wires are in the same cable?
View attachment 325593If not can you list by numbers which form cables?

Are 1 black and 7 blue in the same terminal (looks like B1)

Does the position of switch with brown, black, grey cable make any difference to the porch light? there are 4 combinations of the 2 switch positions: up up, up down, down down, down up.

Yep 1 Black and 7 Blue go to the same terminal (B1). Coming into this hallway switch box are 3 cables which have all been labelled:

'H2 Wall' - which I assume to be the wall lights in the hallway, the 3 wires from H2 Wall are on the right side of the switch in 'A Com', 'A1', and 'A2'.

'P' - Black with red sleeve to B1, and Red to B2

'P2W' - Red to 'B Com', Blue with red sleeve to 'B1', yellow with red sleeve to 'B2'

In the porch, the right hand switch (with the black/grey/brown) turns the porch light on and off

 

[SUNRAY]

Yep 1 Black and 7 Blue go to the same terminal (B1). Coming into this hallway switch box are 3 cables which have all been labelled:

'H2 Wall' - which I assume to be the wall lights in the hallway, the 3 wires from H2 Wall are on the right side of the switch in 'A Com', 'A1', and 'A2'.

'P' - Black with red sleeve to B1, and Red to B2

'P2W' - Red to 'B Com', Blue with red sleeve to 'B1', yellow with red sleeve to 'B2'

In the porch, the right hand switch (with the black/grey/brown) turns the porch light on and off

Ah so presumably the hallway and porch switches are working correctly as 2 way.

This is what I think you have:

Somewhere there is a junction box or another accessory where the red,yello,blue join the brown,black,grey.

Next, how many lighting circuits do you have in the consumer unit (fuse box) and are the porch light and the outside wall light on the same breaker/fuse? If they are I may ask you to have a look in some lights. But in reality I think you will be looking at getting another cable to the porch switch or moving the thicker T&E.