It is a common problem with the BA Falcon. The shaft controlling the flaps breaks. You should be able to hear the electric motor working under the dash when you switch from cold to hot. You need a very quiet area to listen.
To fix the problem. The part cost approximately $61. My Ford Dealer has quoted approximately $500 to fit it. They have to pull out the whole dash to reach the rod.
Sorry about the bad news but if you shop around you might get it done a bit cheaper.
Old Timer, July 2008
