In my house, I have ceiling lights in the hall and landing. I have removed the 2 switches because they were connected as 1-way switches and I want to set up 2-way switching.
I think the necessary cables are already in place, because there are two T&E cables protruding from the wall in both the hall and the landing. But I'm not sure how to connect the switches such that the 2-way switching will occur. I have identified the T&E cable that acts as a normal switch for the landing light when the red and black are touched together, and I have identified the one in the hall that does the same for the hall light. For clarity, let's refer to these below as the "1-way cables".
I can't figure out how the other T&E cable should be used. I assume (though I'm not sure) that it goes from the landing light switch location down to the hall light switch location. I can't think why else there would be an extra cable protruding at each location.
My volt meter reads no voltage across the red + black of the extra cable protruding from the hall wall. Nor for the extra T&E protruding from the landing wall (possibly the same cable).
So I thought I could try using either the red or the black to connect the 'common' terminals on each 2-way switch, and connect the red and the black of each "1-way cable" to L1 and L2, on its respective switch. But that didn't work.
Can anyone provide a link to a likely wiring diagram I can try using - or simply explain, in words, how I should connect the 2 T&E cables at each switch?