Changing A Light Switch...

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Spooks

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Hi.

I'm just an unenthusiastic amateur, so this is proving to be a right pain in the proverbial.

I'm trying to replace a dimmer switch with a normal light switch. Trouble is, there were four grey cables connected to it, with red, black and bare earth wires from each. That means there twelve, count 'em, TWELVE cables connected to this one switch. It's only a one gang one way switch so I can't see any reason for all these.

Anyway, tried connecting just one set to the new switch. Blew the fuse in the fuse box. Been out and bought a new fuse switch but now only two lights in the house are working.

Bought a new light switch as well today. The connections are L1 and L2, N1 and N2, and two for the earth cable.

Any advice on how to proceed would be greatly appreciated as I'm well out of my depth on this.

Cheers.

 
Did you make any notes of connections before you took the old switch off?
Afraid not, wasn't really thinking. I know 3 reds were in one connection and one red in another, and the earths were bundled together. Can't remember about the blacks. Yes, I'm an idiot.

 
Sounds like you have bought an intermediate switch.  you can still use that.

But you REALLY should have taken note of how it was wired. BEFORE you took the old one off.

SOME of the cores will have been linked together with a connector block, you should have left those alone.

Then you might have hat 2 or 3 terminals used on the dimmer. Those were the only ones you needed to undo and connect to similar terminals on the new switch.  If there were any pairs of wires in terminals you shoulf have marked them in some way to ensure they remained paired up properly.

I say all this for the benefit of the next person.  It's sadly too late now. You will need some test equipment and know how to use it to unravel what is what now, so best call an electrician who will sort it quite quickly and it hopefully won't cost much.

Okay, re reading your description, you have "loop at switch" wiring.

So you can do it trial and error.

Obviously make sure the power is off before doing anything.

All earths together into the earth terminal of the back box or if it's a plastic back box into a choc bloc.

All blacks together into a chock bloc.

Now the trial and error bit.

You need 3 reds into one switch terminal, and one into the other switch terminal. Trouble is you don't know which red is the single one. So you are just going to have to try all 4 in turn as being the single one until you get it right.

If you get it wrong, all that will happen is the light switch will turn off half the lights in the house, not the one you intend it to turn off.

 
Sounds like you have bought an intermediate switch.  you can still use that.

But you REALLY should have taken note of how it was wired. BEFORE you took the old one off.

SOME of the cores will have been linked together with a connector block, you should have left those alone.

Then you might have hat 2 or 3 terminals used on the dimmer. Those were the only ones you needed to undo and connect to similar terminals on the new switch.  If there were any pairs of wires in terminals you shoulf have marked them in some way to ensure they remained paired up properly.

I say all this for the benefit of the next person.  It's sadly too late now. You will need some test equipment and know how to use it to unravel what is what now, so best call an electrician who will sort it quite quickly and it hopefully won't cost much.
Thanks, all very sensible that. I sort of hadit in my head that it would all be quite easy so didn't think. Complete numpty. So that'll be me on the phone to an electrician then. Thanks again mate : O)

 
Thanks, all very sensible that. I sort of hadit in my head that it would all be quite easy so didn't think. Complete numpty. So that'll be me on the phone to an electrician then. Thanks again mate : O)
Read the second part of my post (which the forum merged two posts into one) as a way of sorting it yourself.

 
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