Fitting a standard bathroom extractor fan

My old bathroom extractor fan with timer, has finally given up the ghost.I have bought a new Standard fan without timer.I have tried all ways and every which way (within safety guidelines),to wire the b****r up! There are 3 wires, red or orange, yellow and blue, from the mains, and an earth wire, yellow and green. I have isolated the permanent live wire (red or orange),and connected up the blue (neutral), and yellow (switched live), to the two black wires in the extractor fan. Nothing happens. If I connect up to the red or orange live wire instead of the yellow switched live wire, the extractor fan stays on all the time! (The fan is wall mounted up to near ceiling height, and usually switched on, with the light, by pull cord.
Can you advise me please?
Regards,
Thick Jack Clot.(Username only of course)!

Have you checked that the switched wire becomes live, when you switch the light on?

You will need a multimeter on the 250V AC Volts or greater range.

Mosez-Thank you for your very quick and helpful reply! I will check it out. By the way, Im taking the tablets, thanks. And as Sir Winston Churchill said, "KBO!"

First of all TURN OFF THE POWER to the circuit you are working on
If there are colored wires at the old fan remove them first
Then fron your center light in the bath room take two wires red/black or new colors brown / blue they will connect to the fan.
There are two black wires on the new fan one is to be connected to the black/blue wire from the center light the second black wire to be connected to the red/brown wire at the center light
now the brown/red wire at the center light has to be connected to the switched side which is (if you have a rose up it should be the double connection with one red wire connected to it) or if you have a bunch of connectors (not profechional) the one with a single red at it.
the black to be connected to the black side.
If you have dun the correctley the fan should work when the light is turned on and off when switched off.

I would take the advice given by Mosez.

We cannot be sure what the voltage yet ! .. Some fans are fitted within within certain 'zones', and need to be low voltage, maybe your was.

To mosez, ckelly and eddie-thanks guys for your additional help with my problem. I am currently finding all this a bit electrifying, I want to remain positive but I feel quite neutral about it all, so watt can I do?! I had a bout of road rage yesterday, I'm not normally like that. I've decided to fork out and get my local Sparky to sort it!
yours, remaining,
thick jack clot