Heater cable comes through fire wall to tin can that holds the flapper valve. Problem: The controls on the can appear to be reversed. The cable end where the trunnion goes to secure the cable end is on the inside. (toward the back of the car) The clamp that holds the cable sheath is on the outside. (toward the front of the car.) To me, that's backward. By the way, the tin can won't turn end for end as it won't fit into the core unit opening.