quote:
Originally posted by jack deryke:
Fresh (that is, outside air) was only supplied to the '74-and up Panteras. Behind the glove box there was a 2" or so flex-tube that connected to the passenger side cowl opening just in front of the windshield. The tube terminated at a special heater control junction box alongside the heater/AC enclosure. These cars used different heater/defroster controls too, and one selection was "fresh air." All earlier Panteras use recirculated air from inside the cab to supply the heater/AC enclosure.
Jack,
As you recall this fresh air thing as been discussed a lot in the past. The early cars (before #1910 or so) had fresh air supplied to the A/C/Heater box from an elongated vent if front of the windshield under the grill work (the opening is toward the center of the car). On these cars the top A/C control lever is marked AIR � OFF. I�m lucky to be the owner of #1887 that also has the pull for fresh air knob option that directs conditioned air at your legs. But this option did not get installed on all cars before #1910. The really odd thing about all of the fresh air intakes is that they are down stream of the blower fan? Some of the later cars also have fresh air but it comes from an opening to the far passenger side of the grill area and is very small. As I write this, it reminds me that I need to test my A/C outlet temp when the car is at speed and see if I�m getting hot outside air pushed into the car and into the A/C/Heater box. Because the outside air enters from the top front of the box, it looks like some of the air could be flowing in down stream of the evaporator. I�ve noticed that my A/C vent air temp is always higher when I�m under way compared to slow speed and I was writing it off to condenser air flow problems but it just might be that I need to close off the outside air.
Mike
P.S.
How interesting! I just ran a test on the air flow. With the AIR � Off lever in the AIR position, the blower motor on, the car at rest and I found that a lot of air is blowing out of the outside air vent. A lot of air! So it must be blowing some of my cold A/C air out of the car at rest and getting hot outside air pushed in at speed when the air pressure is high at the air intake. I think I just found the cause of why my A/C vent air temp is warmer at speed!
[This message has been edited by Mike Dailey (edited 08-28-2002).]