Converting Dimmer to Standard Switch Problem

[mike_bike_kite]

I thought the two bulbs had gone in my son's bedroom so swapped one bulb and tried again. After fiddling with the dimmer for a while the bulb I hadn't swapped flickered on then went out. I figured it must be the dimmer switch itself.

I don't particularly like the dimmers in my house and my teenage son does smack the poor things every now and then so I figured it would be better installing a normal switch.

The existing wiring on the dimmer was:

• C one blue wire and one black
• L1 a red wire and a yellow wire
• L2 a single red wire

I wired it up the same with the new switch but neither light comes on. The fuse isn't blown. I do have a multi-meter if required.

Any ideas?

[Mr White]

I will guess as there is no specific rule as to what colour goes where.

Swap L2 with C

And always take pictures.

I will also guess the light can be turned on / off from another location?

[mike_bike_kite]

There's only one switch in the room and two little halogen bulbs in the ceiling. Am I still OK to swap the wires over?

Thanks for replying by the way!

[Mr White]

As I said previously there is no specific rule as to what colour does what or where it should go, but, the fact you have a twin and earth and a 3 core and earth implies there is or was another switch, pull cord perhaps?

Yes, still swap them over (The red must stay as it is now, on its own)

[mike_bike_kite]

OK swapped L2 and C over but still no lights. On the plus side I haven't blown all the fuses yet or electrocuted myself!

I was curious about the other switch you mentioned and did eventually find a pull cord hidden at the back of a fitted wardrobe.

Any idea what should I try next?

[Mr White]

The way a 2 way switch is wired (in a nut shell) is one single wire at the top (C)
and two wires in each of the bottom terminals.

So if you had a red single it should be on its own at the top in C (common)
when you swapped L2 and C around, make sure that both wires in L2 are actually making a connection, no harm in checking L1 either.

Since it was working before you changed it, and there are no electronics involved, it has to be a airing configuration error, but you are sure you have them right, so it must be a connection (or not) problem.

[Skid Sprocket]

With a 3 core & earth 2 way switch wiring the yellow should go to the C (common) on both switches with red and blue/black (from the same 3 core cable as yellow) to L1 & L2 and the other 2 wires (from the twin cable) into L1 & L2. This twin cable goes to the light fitting and will not show at the pull switch.

The 3 core cable is really just linking the two switches.

[Mr White]

With a 3 core & earth 2 way switch wiring the yellow should go to the C (common) on both switches with red and blue/black (from the same 3 core cable as yellow) to L1 & L2 and the other 2 wires (from the twin cable) into L1 & L2.

Sorry to say but as i have said before, there is no specific rule as to what colour goes where, so to say Yellow must go to the common is not a definitive response, since it depends on what colour who ever wired chose to use.

And since the op did say he had a black and a blue, and a red and yellow already as pairs........

[Mr White]

Mike bike kite. The pull cord you found, any possibility you could gently take its cover off (it will unscrew) and see what colour wire goes to what terminal?

[mike_bike_kite]

I'll have my next attempt tomorrow morning when it's light. I'll have a go at seeing what the connections are to the ceiling switch but it's at the back of a top cupboard and I'm not sure I'll fit.

Would it help clear up things if I used the multimeter on the various wires?

[mike_bike_kite]

I've attached a picture of the wiring to the other light switch. It's quite difficult to get too so this is probably the best image I can get. Hope it helps.

[Mr White]

Sorry, I am busy today, but what happens if you "switch on" the pullcord?