[kaefer]

Oops, I forgot about the front fan.

Rick,
The early cars use a combination of the engine fan and the front trunk blower fan.

[William Miller]

Maybe I started this confusion.
In the heading of the 1st post he listed 78-83.
Typical confusion. If you put your model and year in your signature it usually helps narrow the discussion as well.

On the SC's I've seen 78-83 the engine heater provides the heat and the freash air blower in the trunk provides the fresh air. It is mixed with the dash controls.
A/C is a completely seperate system with a third blower.

I understand that 84 till? have additional heat blowers in the cabin near your feet.

Earlier than SC's don't have the engine mounted fan (thus Backdate kit). The fan on the motor pushes the air to the cabin. I didn't know there was one up front that sucks it. Thanks Kurt of course I learn something here every day.