Bathroom fan works slow when light is on & works fast (normally) when the light is turned off..

[Rrgwin]

Hi. Any help please. Have a wall extractor fan & noticed recently that when the light is turned on the fan comes on but only quite slowly. Not enough to suck anything out of the room.
Then when the light is turned off & the count down to fan off begins it starts going at normal speed.

Any ideas?
Cheers.

 

[ericmark]

No neutral, it is getting the neutral through the bulb once light turned off.

 

[Rrgwin]

Thanks. I'll check the wiring

 

[Risteard]

Has someone somehow managed to wire it in series with the light? Would be an achievement to **** the wiring up like that though.

 

[sparkwright]

Send a pic - fan (or something else nearby closely related) probably wired up completely wrong.

 

[Rrgwin]

Light switch & fan

 

[EFLImpudence]

Can't tell from that; will need picture of light wiring as well - and/or any junction boxes.