hi. I had my garage converted about 18 months ago and had it set up for outside lights also. I have just eventually got around to putting my outside lights in and then only work when the garage(bedroom lights is on) the bedroom light switch is 1 way with L in com and N in L1 the light switch for the outside wall has a L and a N and then there is a wire that runs behind the light switch and continues up the wall to maybe a junction box in the ceiling? this wire runs outside the the outdoor lights through conduit and under my slabs. so I connected the outside lights and they turn on and off fine but only when the bedroom light is on. has a live and a switch live been mixed up in the ceiling area somehow? I cant get to anything due to the conversion so not sure on what to do to make the outdoor light switch work independently.
Seems the problem is the bedroom, so if you join the L and N (this will be a live not a Neutral) your outside lights will be ok. And then you need another wire from bedroom switch to the light.
I'm not sure. the bedroom works fine on its own. I could maybe work around it through wiring the lights from an outside socket as that's the easiest to get to. the outside socket is a spur though, so if I fit and external FCU next to it with a 3amp fuse in it would this then be fine to power the 3 external lamp posts (6 bulbs)
Because you could create a dangerous situation, you can't do electrical "workarounds" without a full understanding of what's already there. I suggest you take things back to before the conversion ie get the house working properly, and then sort out the lighting in the conversion and externally.