Lord Peter Mandelson, Uk Ambassador
News1 min ago
No best answer has yet been selected by dale1321. Once a best answer has been selected, it will be shown here.
For more on marking an answer as the "Best Answer", please visit our FAQ.Although you say the fuses are okay, is there live at the fuse box? If there is live then you need to check if there is a relay or air conditioning control unit. This will either be next/near the fusebox or under the dashboard (unfortunately I'm unfamiliar with the 406). You then need to check for live either side of the control unit/relay and then trace it back to the switch. Unfortunately it's a case of tracking continuity until you lose the live. Relays are fairly cheap to replace and you could even try it as a 'trial and error' just to see if it then works. If its a dedicated control unit then it could be pricey.
If there is no live at the fusebox then it could be a trapped or damaged wire. Again you need to trace it back. Have a look for a wiring diagram on the net or see if there is a manual you can borrow from a library or friend.