Electric lighting loop circuits

[Ly2512]

I have replaced two light fittings, one in the bathroom and one in the lobby outside the bathroom. Despite having followed the wiring diagrams I made, this now happens:

1. The lobby light works as long as the bathroom light is not on.
2. If both lights are switched on the bathroom light takes on a strobe effect - as does the lobby light.
3. The bathroom light will not operate on its own.
4. The lobby light seems to operate the bathroom light .

As far as I can see, the bathroom light is the last light on the circuit. Have I got the switch cables confused?

Also, the wiring diagram I made for the bathroom light ceiling rose does not comply with current wiring standards. The earth wire from one of the main cables was fixed to the NEUTRAL section, the neutral wire from the same mains cable was fixed, together with the neutral wire from one of the other cables (presumably the switch cable??) into one hole of the LIVE section. The remaining wires seemed to be correctly fitted. However, this worked. When I try and apply correct wiring to this rose nothing works!! Please help.

How do I find out which is the switch cable and which is the mains cable (there is no visible difference)?

 

[breezer]

to find the live incoming you need to test it. I recomend a multi meter, but you can use a "volt stick" which you can get from any good diy store (it lights up when near to a live cable)

it should be wired like