Bathroom fan not working, isolator also disconnecting light Ask questions and find answers to many subjects relating to electrics and electrical work

[Ed99]

My bathroom fan is not working. I will replace it, but I figured out wiring is strange isolator also disconnects light. How do I change the connections so that isolator only controls the fan

Please see photos at the link


https://imgur.com/a/ceiXfMc

[Mr White]

The supply to the light is also connected to the isolator when it need not be. Without testing the cables to see which does what, you will have to follow the cables from the light to the switch to see which is in the wrong place or guess.

If I said move the brown one, the obvious question would be which one, since they are 3 of them you need to test or guess.

[Ed99]

So how should I go ahead with the trials?

[ericmark]

Counting the neutrals and a black, it would seem 4 cables. 3 x twin and earth, and 1 triple and earth, the latter seems likely to feed the fan. I would have expected to find all the fan connections in one side of the isolator and rest in the other side. But can work either way, but would not expect any wire to be in with the fan feed.

But I see grey and black with other wires in the terminals, can't work out which brown is from three core, but I would move other wires in with the brown grey black of three core to other side of the switch.

The blue in L2 is likely the switch wire and a line not neutral, put some tape on it so it does not get mixed up with other blues.

So the three core and the one with a blue in L2 we have identified, of the remaining one is feed and other goes to light, so the cable which we have identified as switch will go between the line feed and line to light.

Looking at the diagram on fan, it seems brown is switched line, gray permeant line and black is neutral, can't see it that well in the picture, so L1 is switched line, L2 is permeant line.

I am just using logic, I am showing how I worked it out in case I have made an error.