Just to give the 'connect into the existing lighting circuit' one last try (it would save me going out to buy an FCU and would just be neater), here are some photos of what's what:
This is the Other End (in the house) of the 2-way switch. It's a double switch, with two 2-way lights, hence the MASS of cables stuffed in there. ALL the cables going in to the switch are either brown, white, grey or black, and ALL the blue cables are connected together, as you can just about see in the red square. However, the cables to the garage go through two junction boxes outside, so it's possible (but stupid) that there's a colour change somewhere between here and there. The whole thing was only installed last year, so hopefully it's all up to code:
This is the garage end. This morning I changed the single, 2-way switch for a double 2-way switch, before the "duh" moment when I realised that I somehow needed to get some power in there for the new garage light (which would be controlled, obviously, by this double switch). You can clearly see the mystery blue wire, and the bit I've stripped off the end for testing. My theory was that I could just bridge across from the Common (is that always live?) to the 2nd switch's Common, then take a wire from the 2nd switch's L1 (or L2 - shouldn't matter) to the new light (this would be the switched live) and extend the blue wire to the light (as the neutral):
But you can also see that there's a mains socket right next to the switch, so taking a spur off that and, as suggested, using a switch FCU as a lightswitch, would not be much effort.
This is the Other End (in the house) of the 2-way switch. It's a double switch, with two 2-way lights, hence the MASS of cables stuffed in there. ALL the cables going in to the switch are either brown, white, grey or black, and ALL the blue cables are connected together, as you can just about see in the red square. However, the cables to the garage go through two junction boxes outside, so it's possible (but stupid) that there's a colour change somewhere between here and there. The whole thing was only installed last year, so hopefully it's all up to code:
This is the garage end. This morning I changed the single, 2-way switch for a double 2-way switch, before the "duh" moment when I realised that I somehow needed to get some power in there for the new garage light (which would be controlled, obviously, by this double switch). You can clearly see the mystery blue wire, and the bit I've stripped off the end for testing. My theory was that I could just bridge across from the Common (is that always live?) to the 2nd switch's Common, then take a wire from the 2nd switch's L1 (or L2 - shouldn't matter) to the new light (this would be the switched live) and extend the blue wire to the light (as the neutral):
But you can also see that there's a mains socket right next to the switch, so taking a spur off that and, as suggested, using a switch FCU as a lightswitch, would not be much effort.
