Extractor fan stopped working

[DiyNutJob]

I have 2 Emcovent EV4T bathroom extractor fans. One in the area that the builders have been playing with has stopped working. I don't know if the fan is faulty or the wires that feed it are. How do I diagnose? I have taken the fan off and disassembled it for cleaning. Nothing in it is burnt. The fan has L N T wires going in. Is there any way I can test it using just the Live and Neutral wires?

Here's the wiring diagram of a similar fan:

 

[terryplumb]

You need to establish voltages present ,do you have any test instruments ?

 

[DiyNutJob]

Yes, I have a 30 year old beginner's multimeter. I did manage to determine the fan was working by connecting it to the wires that the working fan was connected to. The problem is to do with the wiring in the area the builders had been playing with. There is 0V between T and N, so the fan timer was never triggered. L and N is at 240V.

I believe T is the Live wire of the bathroom light switch. Previously, the switch controlled a single incandescent/CFL bulb. Now, the switch is used for controlling 4x 5w LED downlights. Could the new switching arrangement cause the problem? I don't believe so, but I thought I'd ask anyway. The fan was limping 2 or 3 days before the builders finished on their final day. The limp might have been because the fan was old and dirty. It's like new now after I stripped it down and cleaned and oiled.

 

[SUNRAY]

So the builders rewired the lights on which the fan is part of and it stopped working. Call them and issue it as a snag.

 

[terryplumb]

You should get the builders back ,or more specifically the electrician who altered the wiring to the light fittings ,there is obviously a disconnected live.

 

[SUNRAY]

Altenatively find and trace the cable feeding the fan and trace out the arrangements for the new lights, document or photograph and bring the information back and we'll help you cure their mistake.

 

[DiyNutJob]

Well, their final invoice hasn't yet been paid. I am quite sure they will be very motivated to do the right thing.