Replacing a 2 gang 1 way switch with a dimmer

[Mr G]

I took off the old switch and noted the wiring
Red cable into position C and L1 on one transformer
and Blue cable into L1 and white cable into C in the other transformer ( dont ask me why there's a white cable I was surprised to see it myself )

Replaced old switch with dimmer copying the above but no joy
put back on the old swich and lights work
tried dimmer again but no joy. I thought faulty dimmer but replacement dimmer still not working.

Am i doing something wrong

 

[breezer]

you mention transformer, am i to take it that the lights are low voltage, the origonal switch only goin on /off and now you have a dimmer switch?

if this is the case it is the transformer that is the proble, some transformers can not be dimmed (looks like you have one) you can however replace it with a dimable transformer of the same wattage as the one that you have already

 

[spark]

A white cable? That doesn't sound too good...If you're not sure of what you're doing I would get it looked at by someone who does; you shouldn't have a white cable at a switch.

 

[breezer]

unless that is it is a feeble atempt at yellow, or it may look white under a slightly yellow light (colour temperature, but we wont go there)