Arrrg…extractor not working

[prologica]

So, old bathroom extractor stopped working. I fiddled with it a while back but not resolved.
I’ve bought a new Xpelair (no timer). I swapped out the fan and tested the new one but it didn’t run.
Opened the switch (it’s on a two gang switch, one for fan, one for lights) but all looks ok.
As a test I disconnected the lights and swapped the fan cables to what was the light switch. Still nothing.
So I connected the fan and the lights to the same switch and only the lights came on!
I’m a bit of a dunce with a multimeter but while probing at the fan end I got a spark so presumably the cables are ok? (I feared rodent damage)
Any other suggestions? Is there a simple way to test the fan on a different cable run? I have a flex and 13 amp plug but concerned that might blow the fan?
TIA

 

[Collectors]

No chance you have a second fan switch at high level, quite often out side & above the bathroom door that might be off.

 

[RandomGrinch]

I have a flex and 13 amp plug but concerned that might blow the fan?

There shouldn't be any problem connecting a flex - this is only a quick test to check it works.
Many hours can be wasted looking for a problem, when really, the brand new item is at fault.