Strange Wiring on Loop In Ceiling Rose

[avguy]

Hi,

I'm not a sparky but am confident with wiring as work in the AV business and work with cabling a fair bit. Would appreciate some thoughts and advice 

Looking to replace a ceiling rose with a new IKEA light fitting. The old wiring looks to be strange as I would expect the switch live to be connected to the light fitting live, and all other wires connected to same colour (i.e. lives tied, neutrals tied and grounds tied). However I can see that there is two wires (red and black) connected to the light fitting live. Is this definitely incorrect or some type of series wiring? The lights were working fine and as expected. 

Unfortunately all i did was take a picture (can't upload) before taking the ceiling rose off, and now am left with the three flex coming from ceiling. None of which are clearly labelled - one grey flex with brown/blue cores, two white flex with red/black cores. The grey flex was definitely not connected to the light fitting live so it is one (or both?) of the white flex that were connected, one of these has bed tape around the main white sheath (not the black core as expected) so it is probably this one. 

I will do a continuity test on the flex i suspect is from the switch (e.g. the flex with the red tape around it) to confirm that it is from the switch. However once I've established this, do I also need to put the red wire from the other flex going to the light fitting live as well, as it was? Or will it be fine to wire up as I mention above, how it would be expected?

 

[ProDave]

The key is you said "lights" as in the plural of light,

So you have a normal ceiling rose wiring where it ends up with the black core (which should be sleeved red)  from the switch drop connecting to the light L.  THEN you have another twin and earth looping that switched L to the other light fitting, so it has it's black connected to all the other black neutrals, and it's red, connected to that black switched L  from the switch drop.