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After accidentally earthing the live wire going to the outside light whilst putting a faceplate back on (patched up now), the light has stopped working. I've just been out with a multimeter to see if any power is going to the light at all and discovered something weird.

Here is the connector block for the light. (LTR) Neutral, earth and live. Simple enough.

Here is the connector block for the light. (LTR) Neutral, earth and live. Simple enough.

Here is what I saw after testing between live and neutral: Here is what I saw after testing between live and neutral

And here is what I saw when testing earth and neutral: And here is what I saw when testing earth and neutral

Unless I have used the multimeter wrong (very possible) it looks like the light has earthed itself after the incident earlier in the circuit. Have I got that right?

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  • Have you got your wires crossed at the other end? – Majenko Dec 19 '14 at 13:46
  • @Majenko I don't think so. The problem I had at the other end involved what was behind the switch that operated it, which I'm assuming is live and then on to the light. – MrNorm Dec 19 '14 at 13:50
  • Did you blow a fuse or trip a tvss outlet on the same circuit? Perhaps an outlet that's also outside? – Some Hardware Guy Dec 19 '14 at 13:51
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    This is a possible explanation of what you are seeing. If either the line or neutral is broken upstream, when measuring line to neutral gives very low voltage because of the load of the light. Measuring neutral to ground gives coupling noise because there is no load. What do you get between ground and line? If you get full voltage there, then neutral is broken. – rioraxe Dec 19 '14 at 20:51
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    Thanks for all your inputs. As all of the downstairs lighting circuit back boxes are now live, I've decided to be cautious about next steps get some external help with the matter. I will pick post an update when the issue is resolved. – MrNorm Jan 15 '15 at 11:56

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