In my dining room I have one double light switch that controls the centre light and the wall lights. I want to replace this with a double dimmer but am having problems. There are three wires currently to the double switch (excluding the earth to the backplate) RED YELLOW BLUE Currently they are wired like this and work: L1 (empty) L2(Yellow) C(blue) C(small piece of red wire to here and L2) L1(empty) L2 (Red) I thought I could just copy this wiring with the dimmer but it fails to work. Am I mising something obvious?
Morning, The blue seems to be your feed to the switch,and the red and yellow are switch wires going to your light fittings. The blue should be terminated into the C (common) terminal on both switches by using a link between, then the red into L1 on one switch and the yellow into L1 on the other, the yellow and blue should have red sleeving on them to indicate they are live wires and if the switch is metal it will need to be earthed. Let us know your result. Marc
Monkeyman, I see it slightly differently to M-the-S, because it is unclear which L1, L2, and C you are referring to, as there would be 2 of each. Each switch inside the original double switch would have an L1, an L2, and a C (common), and on older switches they are nearly always arranged so the L1 and L2 of a switch are next to each other, and the corresponding C is at the opposite side of the switch. On newer switches all 3 are often on the same side - hence the confusion. My guess is that the RED is the supply Live, and the Blue and Yellow are the 2 load Lives. The L1s are both disconnected presumably because the switch was mounted upside down. My suggestion is to wire the RED to both Common (C) terminals (with the aid of your old link wire) and the Yellow and Blue wires to the 2 different L1 terminals. PS. I'm, by the way, now the self appointed forum expert on 2-way switching - see my thread "Using L2 for neutral?" PP
Hold on a moment (here we go again). I see it differently. In the description it is not clear that each switch is connected together, so they won't both work. More guesswork, then. I think the reference to the short piece of red links common on one switch to L2 on the other (yellow). And I think this yellow is the live feed to switch to blue on it's own switch, and to red (through common) on the other switch. AND indeed the switch is upside down. Therefore, in the dimmer, the YELLOW should be connected to the common and linked across to the second switch common, and BLUE in L1 for one, and RED in L1 for the other. That's if I read the description(and read between the lines) correctly. Handyandy - really
Hey Monkeyman don't look at the thread titled Neutrals in L2, otherwise you'll run a mile rather than get advice on this forum!
Big Thanks to Marc the spark. I wired as he suggested and earthed to the switch as opposed to the backplate. Its all working a treat!
Of course the real lesson is that it is no more acceptable to embark on electrical wiring work without owning a multimeter than it is to use the point of a knife on screws because you don't have a screwdriver, or the heel of a shoe on nails because you don't have a hammer.....
BAS - You're bang on in what you say, I don't think that even a small fraction of the people seeking advice on this site own or use a test lamp - which is all that would have been required to fix this problem. They'll spend daft money on brass dimmers or fancy light fittings - but £20 on a good test lamp? - no way, the neighbours won't be impresed with that.
Monkeyman, I hate being a bad loser, but if I read the OP correctly, the BLUE was originally connected to only one terminal? That being the case, I suggest you double check that it is working correctly and that one light doesn't come on only when the other is on, or alternatively, only when the other is off? PP
you're right its not qite right so I'll give your advice a whirl shortly. There's no winners or losers here just me with dimmable lights
After reading this thread and the 'Using L2 for Neutrals'. I suggest anyone who is not 100% on the operation of a 2way switch go and get one out the Van/Car/Garage etc and put your multimeter (What you haven't got one? Tut Tut!) onto it's 'continuity/buzzer' setting and have a little play for 5mins. If all does not become clear, don't touch electrix again!
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