The heater on my fiesta courier van is stuck on hot when you turn the dial to cold. I've had the stereo out and it looks like the heat/cold dial is wired. Is there a valve somewhere or an electric flap? Its an s reg diesel.

 

heater control valve needs changing. Common fault on many fords of that era that use the same valve.

 

What Warren says ^^

Looks like this at the back of the engine bay with the L and R pipes connected:





Be sure to get the latest one as there are many dodgy batches out there. This is the latest part number:

 

Thank you very much, the above answers all further questions.

 

Just checked the van, and the valve has been removed, and straight connectors used to re-connect the matrix, probably because it was stuck on cold.
Thanks once again for the replies.