Noticed today that the 87 Shelby Z climate control will switch from panel to floor on it's own consistent with throttle application, but only when in recirculation mode. More gas and the more it switches to floor. Switch it back to just cold and it goes back to what ever mode I have it set at. I am guessing it is either the actuator for the recirculation door or the control itself. But wondered if anyone else has had this experience.