Installing 1gang 2 way dimmer????

[MattyK]

Hi,
I have a lounge with a switch by front door and swithch by back food both control the two ceiling lights, I want to attach a dimmer switch to one of the switches
I’ve bought a 400w 1 gang 2 way dimmer. I’ve cables as follows:
Yellow cable with red tape to L1
Blue cable with red tape to L2
Red cable to COM
Light tuna on and of but doesn’t dim just is either full on or half bright, the other switch has no effect.
What have I done wrong??
Thanks in advance 

 

[Murdoch]

You’ve mixed up the connections ....

 

[kerching]

So what terminals did the wires go to on the original switch?

 

[Doc Hudson]

The colours mean nothing without knowing where the were on the original switch. You have a 1 in 6 chance of getting it right without knowing the original wiring, or metering it out between both switches.

Doc H

 

[kerching]

If the lights worked correctly BEFORE you fitted the dimmer then you have wired it up wrong

as I said previously what were the original connections to the switch?    Otherwise we are all guessing

 

[Sharpend]

I’d bet to swap yellow and blue ? But then I’m a gambling man

 

[Doc Hudson]

Com=Red, L1 = Yellow, L2 = Blue,  (which you say doesn't work)

or  Com=Red,  L1=Blue,  L2=Yellow

or  Com=Blue, L1=Red, L2=Yellow

or  Com=Blue, L1=Yellow, L2=Red

or  Com=Yellow, L1=Red, L2=Blue

or  Com=Yellow, L1=Blue, L2=Red

Are your six options to try. 

If the old switch was labelled "Com/L1/L2" and you swapped the cables exactly like for like then it should have worked.

But if the old switch was labelled "L1/L2/L3"  and you have put L1 to L1, L2 to L2 and L3 to Com, then it wont work as Old L1 should be Com, Old L2 should be L1 and Old L3 should be L2.

So you could try rotating them around appropriately, or if still no success you will really need someone with a test meter able to correctly which wire is which. This is of course assuming the dimmer is working correctly and is compatible with the type of lighting you have got. Your point saying it doesn't dim makes me wonder if you have the wrong type of dimmer, also wired up wrong for two way operation. 

Doc H.