Hi I have just sorted this out. As posted the ignition switch was faulty. The way I have fixed it, if you locate the white cable block from the ignition switch & take a feed from the white wire, solder a small length of cable & then locate the brown cable block this is the feed to your heater fan, turn on the ignition & turn on the fan to max & with the not yet soldered end of the wire you have just fitted, poke it in to one of the red wires in the brown cable block, you will know when its right as the fan will turn on. Make a note of what red wire it is and solder them together, tape up the soldered ends and hay presto it fixed.. You will note that the fan will turn off when the ignition is off just as before