2-gang switch for two pairs of wall lights

[VBScab]

First, let me say that I've read the wiki and I've wired lights before but this has me foxed.

The pattress in the wall has:

RB RB RB RB


All the black cables disappear into some rubber tubing on the right-hand side of the pattress, presumably to some connector buried in the wall. Having just had the room decorated, there's no way I'm going to be able to 'debug' that.

The switch controls 2 pairs of wall lights. The left-hand switch switches on one pair and the right-hand switch switches the other pair.

Anyway, the current arrangement goes like this (where we're looking at the back of the switch plate which has been 'turned round' 180 degree about a vertical axis):

[code:1]
RB RB RB RB
| | | |
| | | |
| | | |______________
!--|----|----|-------------------! |
! | | | ! |
! O |____O O ! |
! | ! |
! | ! |
! ?O ____________________| O ! |
| ! |
! | ! |
!--------------------------------! |
|_________________________________|

[/code:1]

(If you paste this 'code' into a text editor e.g. Notepad, the fonts will line up properly!)

The problem is, I can't see the back of the current switch clearly to see how it's wired, otherwise I'd just duplicate that on the back of the new switch, and I don't really want to take it off just yet without being sure I can go backwards or forwards.

I *think* the terminal marked '?' on my diagram is labelled 'common' but can't be sure and I think it's what's fooled me is that there are 2 points where 2 different cables meet (at extreme bottom left AND top centre) where I was expecting only one point. That, and the fact that the black cables don't seem to be involved at all! (BTW, I'm aware that black and red have no meaning of live & neutral here)

Can anyone work out what I need to do here?

 

[ban-all-sheds]

Can't understand your diagram/description - you say the black cables don't seem to be involved, but you show red & black connections to the switch...

 

[VBScab]

Sorry, the diagram isn't perhaps the best....the connections shown are red only. What I was trying to convey was that conventional red/black/earth cabling emerges into the pattress. My original depiction showed both but even I couldn't decipher it in the end!

The description does say, though, that all the black cables disappear into (what feels like) some rubber tubing. I would have posted links to photos if my blasted kids hadn't run down the battery AND the spare for our camera.