[DeTomaso] Blower mystery

[David D Fisher]

I have to start by saying that I wouldn't have believed this if I wasn't seeing it first hand...

My car came with the heater disconnected and the A/C leaking so I decided to pull the heater box apart and check everything before hooking back up.  I had two ruptured coils (frost bite, I suppose), but that's a different story...

When testing the fan, I noted that the fan blades appear to be oriented backwards compared to direction the motor is spinning them.  I turn the fan on and it moves a lot of air around the shrouds, but hardly anything moves up through the heater box.   ( Note that the motor only goes one direction, regardless off which polarity you wire it and it is turning in the direction that the arrow stamped on the housing says it should. )

Upon further inspection of the fans I note there is an arrow also stamped on them but it is pointing in the wrong direction compared to how the blade is designed.   (enlarge the second picture to full size to see the arrow, and the first picture to see the fan blade pitch)
http://poca.com/index.php/gallery/?g2_itemId=36973


Whoever assembled this in the factory did indeed match up the arrows from the fan blades to the arrow from the motor as expected, but the design appears wrong.   I took the fans off the shaft and flipped them over so that they scoop air from the center and throw it out to the shroud.   Walla!  lots of air moving through the box now!

Admittedly, this is still not quite correct as the shroud is somewhat like a turbo housing and airflow is going in the wrong direction for the shroud, but at least the fan is sucking in from the sides  pushing it into the shrouds. 

So, here is the mystery.   Is it possible that someone at DeTomaso purchased the wrong direction fans from the supplier and an unwitting worker installed them according to the arrows and a number of Panteras out there have heater boxes that barely work on anything more than radiant heat?   Seems very strange indeed.


David