Greenwood Airvac extractor fan query

[Rollerball]

In my house there is a small shower room - the ceiling mounted extractor fan is a Greenwood Airvac (can't seen a model number but it will be at least 10 years old).

Uusually when the light switch to the shower room is turned on, the Airvac comes on straight away.

As of today this doesn't happen - the light comes on but what I now have to do to get the Airvac on is to pull the 'stump' of the pull cord that protrudes from the edge of the Airvac - then it will switch on.

I'm guessing a contact problem with the pull cord switch, but how will it have been wired within the Airvac so that it (normally) comes on when the light switch is turned on?

 

[riveralt]

Is it one of these models?
http://www.greenwood.co.uk/media/pdfs/SK200_installation_instructions.pdf
Wiring diagram page 10

 

[Rollerball]

Thanks, but I'm afraid it's not the same as that one. I should take a photo really .....

 

[Taylortwocities]

Model number will be under the cover.

 

[JohnW2]

...the ceiling mounted extractor fan is a Greenwood Airvac ... Uusually when the light switch to the shower room is turned on, the Airvac comes on straight away. As of today this doesn't happen - the light comes on but what I now have to do to get the Airvac on is to pull the 'stump' of the pull cord that protrudes from the edge of the Airvac - then it will switch on.

It would be helpful to try to work out how the fan has probably been wired ... When it was working 'normally', did the fan go off immediately the light was switched off, or did it carry on for a few minutes after that?

You say that the fan now does not come on when the lights are switched on, but does come on if you then pull the stump of the fan's cord. Does the fan then go off when you switch the light off? If so, are you saying that, even if you don't touch that cord again, the fan does not come on next time you switch the light on (until you pull the cord)? Also, does pulling the cord make the fan come on even if the light is not on?

Kind Regards, John