electrical wiring

[Bexhill Bill]

My garage light can be switched on from either end of the garage and i wish to attach an exterior light but run it off of one of the switches. i bought a double switch but which ever way i wire it up it eather stays on permanently or not at all! Have i bought the wrong switch or is it not possible to run a second light from this type of circuit? Thanks in advance.

[sddsddean]

If you want to switch the exterior light on independant of the interior light, you cannot take the feed from the existing light switches. You must get the feed either from the fusebox (if you have a seperate one inside the garage), or you can quite safely 'tee' off the feed cable to the interior light. You can tee off anywhere convenient along the cable between the fusebox(if you have one) or its entry point into the garage, and the first fitting (switch or light)that this cable comes to. Best way to do this is buy a wall mounting box with a plain cover. Switch off the electric. Cut the cable where you have positioned the mounting box. Put the cable into the box using the entry holes. Use a terminal block (a lego block with screws)to splice the new cable onto the existing (this will be coming through another entry hole) and fit the lid (for safety and it looks much neater). Then just wire up your light and switch. Of course you should wire up the light and switch first, then splice last. That way you can still have the garage lights on and see what you are doing!!

[Bexhill Bill]

to sddsddean, Thanks everso much - I thought i was going about it arse about face.

[New Forester]

sddsddean's right. You may find that the live feed for the two-way light comes into the light fitting from above, in which case you'll have to run from there to the switch. To keep your existing garage light as a two-way one, your new double switch also needs to be two-way. You can recognise this because each switch has three terminals, not two. You can use a two-way switch to wire a one-way light though. If you don't understand how a two-way circuit works, make sure you put it back together the same way as it is now -- or ask another question...

[Bexhill Bill]

Thanks New Forester. (I love the New Forest) The switch i bought was a 'two way' with two three terminal sections but even though i wired up the existing garage light to one side of the switch correctly i was unable to wire the second to the single exterior light. I tried what i thought was the correct route but for some reason it didn't want to play ball! Anyway thanks for the info - i'll take a step back and look at it all again next weekend.

[Tweed]

Actually, you will have a permanant feed at one of the switches. If it's not at the switch where you want the extra switch, then its usually just a case of swapping round the twin red cable in the ceilling rose.

[Dangermouse]

This will help http://www.diydoctor.org.uk/projects/lights_and_switches.htm

[Bexhill Bill]

Thank you Dangermouse you're right - a picture says a thousand words! This AnswerBank site is bloody good.....