Switch wire in a ceiling rose

[brianivor]

I am replacing an existing ceiling rose to enable me to fit a new light fitting.

There are two separate black leads and also a pair of red leads linked together in "pass through" fashion.

The new light fitting has terminals marked "live"and "neutral" but neither of the two existing black leads are marked as to which is the switched "live" lead.

I have applied a test screwdriver to both leads (with the light switch on) one lead glows brightly, the other "half bright"

Is this sufficient to establish which is which? - I have a budget multimeter I could use if I was sure how to check.

I hope that you will see this post as not from someone incompetent but rather safety conscious and willing to seek advice rather than take a chance.

Thank you

 

[bathjobby]

A continuity test from the back of the switch to the wires in the rose will tell you which one is the switched live. And when you find it, mark it with red tape in the rose.

 

[brianivor]

Thank you, bathjobby

That makes absolute sense - I presume that the lighting fuse in the main fuse box needs to be withdrawn again.

Just thinking about it whilst waiting for a reply to my post, did the markings on the new fitting confuse the issue - in other words would it have mattered which black lead went where ? (but as I said, I would rather make sure)

Thanks again.

 

[RF Lighting]

http://www.diynot.com/wiki/electrics:lighting:rose