DIY Doctor UK DIY Forums

I have bought a new light for the landing, when i removed the old one there was 3 lots of 3 core wires in there. I thought i had marked them and put them back in the new fitting the same as in the old fitting, however, when i switch the landing light on from downstairs and upstairs all is well until i switch on the bathroom or spare bedroom lights, the landing lights go out or sometimes dim and the bathroom light wont come on nor will the spare bedroom. If i leave the landing light off the bathroom light comes on when i use the switch. Any ideas what im doing wrong please.
Regards Mick.

Hi , there would have been three reds which go in the centre 3 terms of rose marked loop-in, there should be 1 blk with red tape / sleeving on to indicate it is really a switched live from sw.to go in term next to live flex connection (brn/red), the remaining 2 blacks go in the last 2 connections next to the flex(blue/black).
If you mix up the 'blacks' all sorts of things can happen such as you have now, you need to find out which 'blk' is in fact a 'red' do you have any sort of circuit tester? or do you know a friendly leckie as it's quite simple to test if you know how,
B.W. SPARX

Hi
thanx for that sparx.
no i dont have any test equipment except for the old screwdriver test with the light inside and no i dont have a friendly leckie to give me a hand.
one of the three sets of wires is live tho. i put a bulb on it just to test and when i switched the power on it came on permanently. there wasnt a red sleeve on one of the blacks tho but that doesnt suprise me as we have come across lots of problems in the house that have been bodged by the previous owner , the central heating being one of them. maybe i will have to get a leckie in as i have tried every combination there is and still get the same problem. thank you for your help sparx m8 pity you dont live next door to me hahaha.

Hi Mick sorry I can't help more but sometimes it just ain't poss. to do by 'remote'. If you put 3 reds together and seperate blks one of them should go LIve when sw is on & dead when sw. off. if you can find it then that is sw, L to go to lights L term. remaining 2 blks to N term.
Unfortunately everybody thinks lighting is easy but not always so as many ways of wiring & no standards.
I don't have too many nieghbours here in rural Kent, Romney Marshes pretty low head count more sheep than folks (but some of them very pretty on a dark Saturday night) - the sheep that is!!!
good luck
SPARX

Sparx is right. One of the blacks goes to the switch. You need to work out which one it is and put red sleeve on it and treat it different from the other blacks