2 way lighting problem

[Speedy471]

Since moving into my property a few months ago, I have been annoyed by the 2 way lighting I got on my landing light. This light can be controlled by 2 light switches, one downstairs and one upstairs, only problem is that one switch has to be in a certain position for the other switch to operate the light!

The wiring puzzles me even more - on the upstairs switch I have 3 flex one has a red and black one has a single red, and the other has red and black. The red from the 2 core flex goes to the common on the switch and the black terminates in a connector block with the single red. L1 has red and L2 from the 3rd flex.

At the light fixture I have 2 flex coming out the wall, one with the single red and one with red and black. The single red connects to the neutral on the light and the live from the other flex connects to the live cable on the light. The neutral from the flex just terminates in a block - It was attached to the earth point on the fixture but i disconnected it from that!

At the downstairs switch I have 2 flex 1 has live and neutral in L1 and L2 respectively, and the common has a single red (although this single red cable seems different from the on on the other switch as it sppears to be a 2 core cable with the neutral cut (rather than a single red in a white flex which is seen on the upstairs switch and at the light fixture).

Sorry if its long winded, but i tried all the logical text book connections but I blow a fuse every time. If anyone has any pointers or suggestions it would be greatly appreciated, otherwise I just got to live with it!

By the way its relatively old wiring so no earths.

 

[luminaire]

If that bottom cable with the red and cut off black is totally different from the single red to the one upstairs then it would be too dangerous without actually seeing it to advise what to do . It does sound like some idiot has been at work on the wiring which means there are probably more problems elsewhere on that circuit and no doubt on the others as well. You would be well advised to get a competent electrician in to test all your wiring.

 

[ban-all-sheds]

1) I hope the wiring hasn't been done with flex.

2) When you say "neutral", are you sure about that, or do you just mean "black"?

3) "It was attached to the earth point on the fixture but i disconnected it from that!..... By the way its relatively old wiring so no earths.": If your circuit does not have an earth then you must not use lights which require one!

I agree 100% with luminaire - get an electrician in asap.

 

[ColJack]

the "single red" downstairs is the lived feed, the red and black are the strappers to upstairs switch..

the single red in the upstairs switch is being used as the neutral from the light by being connected to the black neutral in the 2 core which also takes the red switch wire back to the light..

the other 2 core is the strappers from downstairs..

you got some messed up wiring there partner..

you need a multimeter and some good deductive logic i'm afraid..

PHOTO's might help us decipher your problem.. ( besides we like photo's... )

you need to check that the strappers are being used as such..
you also need to see if that black wire that is disconnected at the light is the other end of the black wire at the switch..

 

[Speedy471]

Thanks for confirming that this was a tricky wireup and I was not totally stupid! I got an electrician coming in tomorrow to give me a quote on a new CU, so il get him to have a gander at the light switch at the same time. Lets hope its not part of a bigger nest of bodged wireups behind the walls. Im hoping though that it was all wired correctly once upon a time and it just been put back wrong when a light switch or fixture was changed, well il post the outcome if anyone is interested!

By the way the chrome light fixture downstairs is double insulated - So am i right in thinking that its ok to use without an earth wire?

Thanks

 

[Speedy471]

Ok, someone asked if they could have some pictures. Here they are:

This is the upstairs light switch - note there is a single core cable running into that terminator block - if you could call it that!

This is the downstairs light switch - note the black core it cut so only a single red core comes out of one of the cables.

my phone died for the last picture of the fixture but it appears that the single red core cable goes to the lights blue, the red from the double core goes to the brown on the light and the black from the double core is just connected to a connector block and taped up.

Like i said before i got an electrician coming round later to give me a quote on an RCD CU so ask him about this at the same time!

 

[ColJack]

try swaping the 2 reds round in the top picture.. without being able to identify the switch terminals I can't be certain. but common sense says to me that the common terminal would be the center one? no?