New light fitting, Switched Live Identification

[HitOrMiss]

Hello all, this is my first visit here.

Got a problem with fitting a new light. It is one light (at the top of the stairs) and is controlled by two switches, one at the top, and one at the bottom of the stairs.

I took the wires out of the old rose without making a note of where they came from. (stupid I know)

I know this is how to wire it:

The only problem is that the two black wires should be one Neutral and one switched live. Trouble is they are both just plain black wires and I have no idea which is which. Does anyone know how to identify which one is which?

Thanks in advance

 

[Chri5]

Make a circuit tester (bulb and battery, door bell) or get a multimeter.

Then isolate electrics, then use some wire for test between cable in ceiling rose and switch.

When you have the right wire across the meter (resistance /ohms / continuity) or bulb / bell (light or buzz) you will have completed a basic circuit and the mter / bell / bulb will action.

Circuit being switch to ceiling rose---> test wire----> tester----switch.

Or wearing my cowboy hat, wire it up and see if it works. If it doesn't, you've used the wrong wire (and there's a 50% chance, feeling lucky?).

 

[HitOrMiss]

If I was to wire it up and I got it wrong wouldn't it blow?

 

[bernardgreen]

If I was to wire it up and I got it wrong wouldn't it blow?

No it won't blow if you get the two blacks reversed to the lamp as long as the two reds are the way they are now. It will work which ever way you put the blacks to the lamp.

But it is good practice to identify which is the switch cable.