Garage wiring question

[CortinaV8]

At the moment I have two switches in my garage, one at the front that switches on half the garage lights, one at the rear that switches on the other half.

What I want to do is change the wiring so that all the lights can be switches on or off at either switch.

Dont suppose anyone could explain or draw up a quick diagram, its driving me mad trying to negotiate my way thru the garage at night, its around 20 meters long so not exactly small, lol.

 

[davy_owen_88]

Can you get access to the wiring in the ceiling?

What you need to do is get yourself 2x 1-gang 2-way switches, a length of 3-core and earth cable sufficient in length to span between the 2 switches at either end of the garage, some 5/6A terminal blocks, some green&yellow 3mm sleeving and some brown 3mm sleeving.

Firstly you need to isolate the power and confirm that the circuit is dead (don't use a neon screwdriver for this!)

From this point on we really need to know how the lights/switches are wired. Do you have junction boxes/ceiling roses or are the connections made at the switches? If you can post a few pictures of what is behind the switch plates then we will be able to tell you what to do with a bit more detail/accuracy.

Ultimately what you want is a length of 3-core and earth between the 2 switches, a link between the 2 sets of lights, and then to remove the cabling between one of the switches and the appropriate lights.

 

[CortinaV8]

All the wiring is clipped to the beams
joints are made in JB's
T&E to each fitting
T&E also to each switch.

Can take photos later if required

 

[davy_owen_88]

All the wiring is clipped to the beams
joints are made in JB's
T&E to each fitting
T&E also to each switch.

You currently have a setup like this only with numerous light fittings...

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• davy_owen_88
• 16 Oct 2008
• 2

After you have isolated the circuit and confirmed it is dead you need to chose one switch and remove the cable between it and it's associated junction box. From that junction box you should then be left with a supply cable coming 'in', perhaps a feed cable going 'out', and a cable going to the light/s.

Using a length of 1.5mm² twin and earth, link the 3 terminals at each junction box that is used to supply the light fittings (by that I don't mean join phase to neutral and neutral to earth but to link the phase of one JB to the phase of the other, always being careful that you are connecting to the terminals that supply the light, and not anything else. Remember to sleeve the bare earth conductors with green&ampyellow sleeving). This connection has linked the 2 banks of lights together.

The other option is to link the 2 banks together at the rear of the lights instead of the junction box, either way it makes no difference.

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• davy_owen_88
• 16 Oct 2008
• 1

If there isn't a supply to another junction box, an easier method would be to disconnect all cables going to that junction box and just link the supply cable to the light to the terminals at the first set of lights...

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• davy_owen_88
• 16 Oct 2008
• 2

Now disconnect the 1-way light switches and run a length of 3-core and earth between them. Connect the brown core to L1, grey core to L2 and the black core to C, and then make exactly the same connections at the other switch. Then connect the brown core from the twin and earth to L1 and the blue core (that should have some brown sleeving over it) to L2.

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• davy_owen_88
• 16 Oct 2008
• 1

or

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• davy_owen_88
• 16 Oct 2008
• 3

PS I know the drawings are poo, but I don't have all day to make them pretty

 

[CortinaV8]

Spot on.

Makes perfect sense to me, shall have a go at the wiring this weekend. No idea why the previous owner wired it in like he did.

 

[ban-all-sheds]

Probably because he couldn't be @rsed to put any effort into learning how it should be done, reading DIY and electrical installation books, searching websites etc, and couldn't find anyone to design it for him.

 

[holmslaw]

..

 

[CortinaV8]

You may be right holmslaw, mine actually has a car in it, 1972 Ford Cortina V8 (5.0) I keep the more expensive VW Golf/BMW Mini outside, madness.