wrote:

I have extended my upstairs lighting circuit by a couple of fittings
in the loft.
Workmen have been in and out and when I came back home today I found
none of the lights work.
The RCB hasn't tripped.
There is power (according to my detector) running through all lighting
supply cables and flex. That is true when switches are turned on and -
this is the weird bit - is also true when the switches are turned off.

Lighting circuits can be hard to find the cause of a fault, as they are
all connected together, with a spaghetti mix of wires in each light
fitting.There is (on many circuits) a live feed to the fitting, whether
the switch is on or off.

I think I'd start by going round each switch, and testing for voltage at
the switch with a multimeter.
When you find one with no voltage, then the fault will lie with either
that fitting, or, the previous or next one along. You'll need to trace
which route the wires take to see which way they run.
It is likely to be 1 or 2 wires that have come loose inside either a
light fitting, or a junction box.

Also, you dont sound too clued up about lighting circuits, so maybe you
should get someone in to sort it for you, rather than risking a shock?
Alan.

--
To reply by e-mail, change the ' + ' to 'plus'.