Hi i am trying to replace old switches with new chrome ones,i have a single switch near my door entry with a red,blue and yellow wire,which controls the hallway light which is connected to the 2 gang switch at the other end of the room.In the two gang switch across the room i have three cables coming in,1 cable has 2 red wires and an earth and 2 cables have red,blue,yellow and earth which in turn operates my upstairs landing light,which has another load of cables and a 2 gang switch that operates 2 lights 1 at each end of the landing.i have no idea how to reconnect the wires now as my old switches seem different to my new ones,the old had L1,L2,the new ones have not,i need to know where the wires reconnect.can anyone draw me a diagram..i am a complete novice with electrics and should never have tried with out an electricians help,but i have a very empty purse and an even emptier blonde head..please help as i am now using a torch to climb the stairs.
wiring switches
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1. MAKE SURE THE POWER IS OFF
From the sound of things, the first switch you mention has only ONE set of cables, coloured red, blue and yellow (plus earth). I would normally wire Red=C, Blue=L1 and Yellow=L2. The second switch, with one twin red and two red/blue/yellow cables needs more care. If you have mixed up the two R/Y/B cables careful experimentation will be required.
To one of the two switches (say the left one) connect the permanent live red and the red of the RYB to terminal C. Connect the other red with the blue to L1 and the yellow to L2. (If you cannot identify which red is which you will need professional help.) On the second (right) of the 2-gang switch connect red to C, Blue to L1 and Yellow to L2. Make sure all the earths are also reconnected (VITAL) and do the following tests with a multimeter (MAKE SURE THE POWER IS OFF!!!!!!) Set the multimeter to Ohms. On Switch One prod C to L1 and then C to L2. Note which one has zero (or close to) resistance. If both do, throw Switch1 and try again. Go to switch 2 and throw the left switch. Re-prod back at switch 1 and you should now have zero resistance across both C-L1 and C-L2. If this is NOT the case, swap the two RBY cables completely at switch two and re-start the tests. If it is still inconclusive, you will need professional on-site help. Don't be tempted to experiment with various permutations and combinations, that would be a recipe for disaster.
If all the resistances test out OK, then screw the switches onto the back boxes (making sure that all the earths are connected) and turn on the power. Test the lighting. If it all works OK, you have won. If not, sorry, but you will need professional help!
From the sound of things, the first switch you mention has only ONE set of cables, coloured red, blue and yellow (plus earth). I would normally wire Red=C, Blue=L1 and Yellow=L2. The second switch, with one twin red and two red/blue/yellow cables needs more care. If you have mixed up the two R/Y/B cables careful experimentation will be required.
To one of the two switches (say the left one) connect the permanent live red and the red of the RYB to terminal C. Connect the other red with the blue to L1 and the yellow to L2. (If you cannot identify which red is which you will need professional help.) On the second (right) of the 2-gang switch connect red to C, Blue to L1 and Yellow to L2. Make sure all the earths are also reconnected (VITAL) and do the following tests with a multimeter (MAKE SURE THE POWER IS OFF!!!!!!) Set the multimeter to Ohms. On Switch One prod C to L1 and then C to L2. Note which one has zero (or close to) resistance. If both do, throw Switch1 and try again. Go to switch 2 and throw the left switch. Re-prod back at switch 1 and you should now have zero resistance across both C-L1 and C-L2. If this is NOT the case, swap the two RBY cables completely at switch two and re-start the tests. If it is still inconclusive, you will need professional on-site help. Don't be tempted to experiment with various permutations and combinations, that would be a recipe for disaster.
If all the resistances test out OK, then screw the switches onto the back boxes (making sure that all the earths are connected) and turn on the power. Test the lighting. If it all works OK, you have won. If not, sorry, but you will need professional help!
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