Topic: Heater Box Assembly Fresh Air Door - Dearborn Running Change

[mmus65tang]

Would a late build 1966 Fastback - August 66 (12V), Dearborn car have a heater box assembly with a fresh air door that pivoted up and down or pivoted left to right? Or is either acceptable for a late build Dearborn Mustang?

[Hipo giddyup]

Hello,
   I too have a late production 66' Dearborn Mustang. A coupe with a door tag date of July 21, 1966, and it has the fresh air door that pivots up and down. This car has been in our family since 1976 and the heater box was never repalced by us so I am certain it's original. My Oct. 66', 1967 coupe has the same identical door that pivots up and down. I would guess that the change from pivoting left to right , to up and down occured sometime late 66' production? It would be interesting if others can chime in on more facts.

[J_Speegle]

Took a look through what I have and I don't really have any late 66 Dearborn examples   to offer.  So leaving just one to show the left to right version for comparison

6F2056xx

[outlawincorporated]

Interesting topic..........

i recently purchased a great deal of original parts that came from 6F07C718*** with a schedule build date of 29th July 1966.
in the parts i got was a mint heater box and heater plenum with yellow ink stampings on both of 22nd july 1966 or 6G22. this heater box does have the flip up door not the traditional side opening style.  this was the third example of this style i have come across over the years.

the first example i had confused me for many many years as i thought it may have been a heater box from another ford vehicle, then in 2015 i inspected a late built unrestored 66 coupe x dearborn that had a flip up heater box door, so my thoughts changed that there must have been a design change/update towards the end of the 66 dearborn production year.  whether that design continued over to 67 i have no idea!!!!

not sure this flip open door style has ever been researched by anyone and most people would probably look past it when viewing a heater box in the car, but it becomes very evident once removed from the car.

just another cool feature to our cars.

Regards

PHILL BERESFORD
MELBOURNE.
AUSTRALIA.

[mmus65tang]

I purchased my August built Hipo fastback in 1981 and shortly after owning the car I noticed the heater fresh air door opened up and down and not left to right like I was use to on other 65-66 mustangs. I soon figured out that the up and down door opening was correct for 67-68 mustangs. So, I assumed since my car was built late in the 66-production year that a 67 unit must have been installed if the assembly line had run out of the left to right door units. I recently noticed that NPD list a heater box case “66-68” Top hinge door, 67-68 w/o AC. And under “Applications” lists 1966 mustang Late w/upward opening. Now I have a couple of verification from other late 66 production owners that they also have the up and down opening fresh air door. So, it appears there was a change to the late production cars in Dearborn to the up coming 67-68 style. I am in the process of restoring my car and have a very nice heater box unit already restored and ready to go, but it has the left to right fresh air door. So, I feel for correctness I need to use the up and down fresh air door style. Unless one of the experts on this site says it is ok to use either style.

[J_Speegle]

Edited my earlier post since it only showed earlier examples. But at this point it it appears that you have three examples that all support the possibility of the newer version being introduced into production during 66 production at Deaborn

Guess I need to start a 66 Dearborn Running Changes sticky and we need to continue to look and document more examples when found