2 way wiring help.

[assettt]

I have been replacing the lamps in the downstairs hall and upstairs landing both of which have 2 way switches. I managed to wire the downstairs one correctly and it's working fine and then went upstairs, removed the old ceiling rose and connections and then tried the wiring. Unfortunately the lamp is on even and flickering when the switch is off and only turns bright with the switch on. Also the bedrooms lights are not working now but the upstairs bathroom light are working fine. I've looked at the diagrams on the sticky for help but I seem to have 4 cables with 3 cores each. 1 cable has the expected brown, blue and yellow/green wires and the other cables each have red, black and neutral. I think I have correctly identified the switched live but I'm stuck where I'm going wrong.

 

[ricicle]

It sounds like you haven't got the switch wiring correct. You will need to physically trace the switch wire or use a multimeter to find it. Either way you are lucky you haven't caused a short-circuit.

 

[assettt]

Thanks for the quick reply. I'll go buy a millimeter. What readings should I expect on the live wires. I've never used a multimeter before.

 

[ricicle]

Please don't do any live working.

With the power off and the multimeter set on the continuity/ohms range (as small as possible) you should see no change in the reading when you are testing across the two conductors of the switch wire with the switch open. When the switch is operated the reading should change to near zero.

 

[sparkwright]

As this is an upstairs light you may have access to a loft space.

If you do you should be able to trace the switch cable.

The black/blue of this goes to the switch live terminal (where the brown of the pendant is).

The red/brown goes to the centre loop terminal (or a connector block) with the other permanent live wires).

All remaining blacks/blues should be the neutrals.

The cable with the brown and blue is the result of a recent extension/alteration. Loft light or tv amp perhaps?

I assume you just have the one landing light?
If there is a second the red/brown of that particular cable will go to the switch live terminal. Since you have not mentioned two landing lights I presume you have just the one.

Isolate all power and verify before you work on the circuit.

 

[assettt]

Many thanks. I'll try trace the correct switch wire and will report the outcome here.

 

[ban-all-sheds]

I'll go buy a millimeter.

This looks ideal for a household starter set - multimeter, voltage indicator and dedicated continuity tester, all in a handy case: http://www.amprobe.eu/de_DE/showproduct/115/Junior-Set/

PDF brochure: http://www.amprobe.eu/de_DE/downloadfile/115/beschreibung_1/

All in German, unfortunately, as is the blurb on each product:

Multimeter: http://www.amprobe.eu/de_DE/showproductdata/487/Hexagon_55/

Voltage indicator: http://www.amprobe.eu/de_DE/showproduct/116/2000_α_(alpha)/

Continuity tester: http://www.amprobe.eu/de_DE/showproduct/481/TESTFIX/

but it is sold in the UK - the company is now owned by Fluke, and I guess they haven't got all the websites sorted out yet - contact them (http://www.fluke.co.uk) for info on where to buy.

Right now the English specs are still lurking on the Internet Time Machine from when Beha was an independent company:

http://web.archive.org/web/20060920022629/http://www.beha.com/files_uk/multimeter/93549.pdf


Also see another discussion here: //www.diynot.com/forums/viewtopic.php?t=26282

 

[assettt]

Thanks to all . Tracing the switch cable via the loft was good call. Enabled me to correctly identify which was which. And as you said the blue/brown cable was recent addition for the smoke detector.