Extractor fan wiring is baffling me.

[John7595]

Hi, I'm trying to replace an old/possibly broken extractor fan. We've recently moved into a 1930 era house, and a fan in the shower does not work. I had a look and it wasn't connected, the wires could not reach the terminals in the fan. So I couldn't replicate the existing wiring.
There are 2 cables each with live neutral and earth.
Q1 - The fan is double insulated (box in a box symbol) so I don't need to earth anything here?
Q2 - The fan requires live, switch live and neutral. So what do I do with the 'spare' neutral?

My multimeter tells me that the wires are connected and working, yet the fan is not playing. This is regardless of whether the light is on or off.
Is this a fixable problem, or do I need to call in a ninja??

 

[PrenticeBoyofDerry]

A1) if an earth connection is not required and termination point is not available inside the unit, sleeve each then connect both earth cables together in a connection block. Don't just snip off as you may need them in the future and are also helpful for continuity and Zs.
A2) Have you tested the cables to see which ones are your switched live, permanent live and neutrals.
Hopefully the two reds will offer your live connections (switch/permanent)
and the two black will be neutrals, if that is the case just terminate the neutrals together.
My turn
Q1)Did the old fan come on when the light was switched on?
Q2)Did the old fan have an overrun on, so the fan stayed on for a period of time after being switched off?

 

[securespark]

If there was a timer, one cable would supply permanent live / neutral and the other a switched live or other combo.

 

[John7595]

The plot thickens!! After popping the light out I have found two cables unconnected to the light. I may soon solve this, or be found twitching on the floor lol. Thanks for taking time to help.