Too Many wires for my Dimmer Switch??

Hi , I hope you can help. I am trying to replace my double dimmer switch. Wires are 2 red and 1 black for each switch , plus an earth wire.
Do i connect each red to the L1 and L2 (on each side) and the 2 blacks into the 2 'wavey' connectors (one on each side again). I tried this and it worked OK until I scewed it back on the wall , at which point .. I switched it on again and the main fuse blew ??
Any help much appreciated.

Either you have pinched a wire against the screw when fixing it back, or the back box is too shallow to accomodate the dimmer.

Thanks a lot ! I have now redone it , and guess what , there was a'pop' behind the switch , and the upstairs one (the one that I've been having trouble with , doesn't work again ! Ah well , at least I'm only back at square one !! Will try again tomorrow. Whilst I'm here , maybe you will be good enough to help me out a bit further. The reason all this started is that the side of the dimmer that works the landing light has to be switched on for the upstairs switch (again for the landing light) to work !! I'm guessing that the downstairs dimmer is/was wired incorrectly anyway. Its a new(ish) dimmer that was on there , where all the other licht switches are old and pretty standard. Maybe it was wired wrongly when it was originally changed to a dimmer. Am I right in suspecting that the arrangement of wires in the upstairs switch should be mirrored in the 'landing' side of the downstairs switch? . Many Thanks

Can you send clear photographs of the wiring at both positions?

You're on the right lines that the wiring at each 2-way landing switch should be similar, at least the 'common' wire would normally be the colour.

If you can't send photographs, describe EXACTLY what cables you have, and explain where the wires from them connect to.

Hi again , This is a picture of the standard switch on the landing.
Red in Com , Red in L1 and 2 Black in L2


Below is a picture of the back of the dimmer downtairs. As you look at it , its the right hand side that operates the Landing light (The left side does the Lounge light and is working fine)


The right side is wired from left to right Comm Red , L2 Black L1 Black.

This is as it was wired before.

To go through the problem .. This all worked fine for 3 years (except that you had to have both the downstairs switch (the Landing light side) AND the upstairs switch , BOTH switched on for the Landing light to work. THEN , a few weeks ago , my son switched the upstairs switch , heard a 'pop' and assumed the landing bulb had blown . It hadnt, replaced bulb , still no joy. Local lad (no qualificaions) looked at all 3 items (ie both switches and Light)and could find no evidence of carbon etc. He however concluded that the downstairs switch was at fault. (Dont know why). So .. Replaced downstairs switch and whilst off the wall initially, it seemed to work OK (but as before ref both switches had to be on for Landing light to work) but i hadn't connected L1 Black securely. Thereby blew the main fuse when I screwed it back on the wall ! Connected the wire securely and switched on again .(NB havent used the 'dimmer' facility .. Just plain on/off) and this time heard a 'pop' and right hand side of the switch (ie the landing side ) again doesn't work . Lounge side still OK.
I really hope you can help because folks who dont know what the problem is, but continually try to give me advice are starting to get on my nerves !! Many Thanks

Ps: you will have noticed that I got the wire colours wrong in my 1st post. Sorry !!

It would be helpful to see a photograph of the wiring at the 2-gang switch as well, and to explain exactly what you have and haven't altered.

Hi again ,

This is a photo of the downstairs wires, as you can see it's virtually impossible to work out which wires come from which cable as the cables are hidden above mounting box and all but one of the wires (5) have 'extensions' on them!!
For info it is wired (ref downstairs light .. the one that is working .. Comm = wire 1 / L1 = Wire 2 / L2 = wire 3 (seems to be working fine).
Left side of dimmer (ie landing light side , which we know is and was wrong .. Comm = wire 4 / L1 = wire 5 / L2 = wire 6 NB wires 2 and 5 kinda got overlapped when I was trying to seperate them for the picture , so although '2' appears to be on the left , it is actually on the right when wired up and vica versa.






ie: left hand side of dimmer (which operates the landing light ( 2 pics)




Right hand side of Dimmer (operates Lounge light and working (2 pics)





Thanks for helping me out !! Do you think this is 'solveable'?

Sorry . Forgot to answer your other question !! My young son is positive that the wiring on the 2 way is exactly as it was. (he did the wiring) and that may well be the case , as, having 'blown' the landing side of the dimmer, that side obviously doesnt work at all now. I was hoping that before we messed up another (expensive) switch, that we could get the wiring correct so that both the dimmer and the upstairs switch could operate the landing light independently, rather than having it as before when you had to have both switches on for the light to operate. !!
Again , many thanks for your continued interest. x

Thought you said there was just two reds and two blacks in the downstairs switch?

And are there two blacks in one of the upstairs switch terminals?

You could do with finding out:

Which cores are live with the electricity energised.

Which cores link the two switch positions.

Which core goes to the landing light fitting from the landing switch position.

Perhaps to save ruining more dimmers you could get it working with cheap standard plastic rocker switches then swap to the dimmers once you get it working!

Hi 1John
Thanks for your reply . Please Dooon't think I havent already thought of that !! I have 3 (£1 each) for info.