Classic/Antique Car Repair: heater controls, 66 mustangs, air ports

Question
QUESTION: I own a 66 mustangs and I can't figure out how the heating and or cooling controls work. I know it sounds so silly, but I can't seem to figure it out or find the owner manual. It always feels hot when I'm driving and I've tried putting the controls every direction they can go. There are 3 levers that run vertical and one above them that run horizontal with 3 settings. Any help would be great. Thankyou.          -brandi

ANSWER: Hi Brandi:
Do you have the "Under Dash Air Condition with the for air ports"?
If so, you should have three vertical levels on the dash and two knobs on the air condition unit. One for FAN and one for TEMP.

The levels control heat and defrost while the two knobs control the air condition. If you don't have this four port unit under your dash, then you don't have air condition. It was a rare option for 66 mustangs.

---------- FOLLOW-UP ----------

QUESTION: Thankyou so much for your speedy response. Now, I don't believe my car has air condition, and it only has one knob, do you know which direction they need to be in to be on and off, the 3 levers that is.

Answer
Hi Brandi:
I believe your three vertical levels are (from left to right)

1. Air Vent / Blower
2. Heat Control
3. Defrost
4. The Horizontal level is a mystery. Unless it opens and closes the Vents

However, I could be wrong. The best way to test these is to experiment with the first thing in the morning while it is still cool outside. Test each one separately to see what function they provide. If any of the levels do not function, then you won't be able to determine what it really does. Let me know if this is the case and I will see if a manual exist somewhere.