I've no idea if I'm being honest.scratching my head all morning yesterday,I've done a few in my time but this ****** has got me stumped.i don't even know what the yellow cable is for,someone said it could be a strapper but I've no idea what one of them is.
If you have no idea what a strapper is... and you are trying to resolve a fault on lights controlled by two-way switching then you are probably going to struggle and can easily reconnect accessories incorrectly, with some parts appearing to work but not from both switches!
When you say that the one light works...
Does it actually work correctly from BOTH switches, or just one switch?
The photos of the front of the switches and the one light fitting already up on the ceiling are of little use if trying to diagnose faulty wiring...?
You actually need to see what cables are connected at the switch terminals.. and the light fittings..
e.g.
A standard single 1-way switch has:
a permanent live IN from the supply,
a switched live OUT to the light fitting(s),
the neutral is connected from the light fitting(s) back to the supply, to complete the circuit.
Whereas a pair of 2-way switches are generally wired in one of two methods:
Method A
A permanent live from the supply is connected to the "Common" on the first switch,
{sometimes labelled (C) or (L1)}
two 'Strapper' wires are connected from the 2-way positions on the first switch to the 2-way positions on the second switch,
{Sometimes called (L1) & (L2) or (L2) & (L3)},
a switched live OUT from the "Common" of the second switch goes to the light fitting(s),
the neutral is connected from the light fitting(s) back to the supply, to complete the circuit.
Method B
three 'Strapper' wires are connected like-for-like between all three terminals, common + 2-way positions between the first and second switch,
A permanent live from the supply, and a switched live out to the light fitting(s)
are connected across the two strapper wires that are NOT connected to the common terminals.
So basically you need to be able to identify.. Permanent live, Switched lives, Strappers, and interconnection method between switches..
AND be aware that at the light fittings/or switches there may also supply feed out to other lights on the circuit.
AND there may be some other cable joints that you cannot see in junction boxes concealed between ceiling of floor above, so the same colour cable may not appear at switches/light fittings!
The bottom line is that 2-way switching is quite basic stuff and problems should be easily resoled by a competent person with appropriate test meter(s) within probably half hour tops.
So if you really are struggling it may be quicker to get someone in to fix it for you...?
I have lost count of how many light switches / fittings that no longer work I have had to fix due to a DIY replacement related problems...
Assumptions that Reds/Browns must be live supply and Blacks/Blues must be neutrals and no idea what Yellows/Greys or strappers are??? are some of the key problem areas that resulted in my visit(s).