Specloc....."With the lights switched ON, (all bulbs known to be working)."
My understanding is that the bulbs should have been removed at this point?
Or have I had more rum than was good for me (n.b. it IS half past one in the morning down here in welsh wales!!!)
I think the second point here..... bit too much rum;\
We need to read a continuty bridging two circuits through the loads.
The fundimental problem is that;
Two seperate circuits, supplied from seperate MCBs/Fuses,
Through two seperate functional switches & loads
are combined together on the neutral side
"before the neutrals are back at the CU".
The reading you typicaly get will be 50 -70ohm through the bulb(s) that are actually bridging the two circuits.
You can read it though the neutral side or live side....
But I tend to find this problem is on older installtions wired in singles.
where the neutrals are all bunched into a handfull of terminations on a small neutral bar in an old 6 or 8 way wylex type box.
Where it can be hard to work out which neutral belongs with which live...
so I just find it easier to test on the phase side where I know the two outgoing light wires from the fuses they connect onto!
again I think the picture on my previous post makes it clearer...
It is one of those subjcet that drawn out is easiser to see than explained in writing.