DIY Doctor

Main navigation

replacing a light 3 red and 3 black wires

Postby abbymills » Fri Apr 25, 2008 7:40 pm

i thought i would be really clever and replace the light in the hall way, it was a really ugly bowl type thing which looked like it belonged in a bathroom.
i took it off without looking at which wires connect to which, i am now trying to fit up a set of halogen spotlights which are mounted on a plate, thought it would be straight forward live= red. black=neutral but there are 3 red wires coming down and 3 black and also the earth wire.
i did connect it up it worked for about 10 seconds with only one bulb working instead of all 3, and then it fused when i switched it off and then back on again, so i disconnected it. although now none of the lights in the house are working has the fuse blown completely or do i need something attatched to those wires for all the others to work? and how am i suppose to connect my light up also!? in darkness, with night time drawing in! :(
Rank: Labourer
Progress to next rank:
Posts: 1
Joined: Fri Apr 25, 2008 7:28 pm


Simply Build It

Postby Sheffield_sparky » Fri Apr 25, 2008 10:01 pm

Hiya there. It sounds to me like your house is wired in a method known as loop in loop out. If you have acces to a multi meter then it is quite simple. Check there is no power to the circuit and connect the multi meter between red and black of each cable. Leave the switch open and test resistance (ohms) between each set untill you can identify which one is the switch wire. Once found keep the black wire of this cable to one side. The remaining black wires want to be blocked together as these are your neutrals and all three reds want to be blocked together. Now place the brown wire from your light fitting with the single black from your switch wire and the blue with your two black neutrals. Failing this seek a qualified electrician that has part p certification.

hope this helps
Rank: Labourer
Progress to next rank:
Posts: 3
Joined: Wed Mar 12, 2008 7:54 pm

Postby ericmark » Sat Apr 26, 2008 12:16 pm

All reds together but not to lamp.
The two neutrals black go together and to return on new lamp but not the black switch wire.
The black switch wire goes to Line on new lamp normally brown.
The black switch wire should have a red sleeve on it.
If not then some testing is required. You can use fitting to do tests with but I'll wait to see if you need it first.
Hall way light is not Part P I think Sheffield_sparky saw like bathroom and read it as bathroom.

Postby Timberryuk » Sat Oct 21, 2017 7:00 pm

Ok, new problem, really frustrating! Three red wires, two black, and three earths (I assume). Can’t see the switch so can’t check which wires go there. Anyone got any clue which wires to connect to ceiling light. They’re numbered in the pic. Many thanks for your time!
Rank: Labourer
Progress to next rank:
Posts: 1
Joined: Sat Oct 21, 2017 6:30 pm

Postby ericmark » Sat Oct 21, 2017 8:09 pm

Some very nice electricians use triple and earth to the light switches of bed rooms so if at a latter date some one wants to convert to two way switching the wire is already in the wall, So cable with yellow is likely switch cable.
Rank: Project Manager
Posts: 2619
Joined: Fri Oct 02, 2009 8:49 pm
Location: Llanfair Caereinion, Mid Wales.

Display posts from previous
Sort by
Order by

  • DIY How to Project Guides
  • DIY how to tutorial projects and guides - Did you know we have a DIY Projects section? Well, if no, then we certainly do! Within this area of our site have literally hundreds of how-to guides and tutorials that cover a huge range of home improvement tasks. Each page also comes with pictures and a video to make completing those jobs even easier!

  • Related Topics