well id post a pic but it's too simple.

Without taking anything apart one would be able to adjust the linkage by sticking a phillips head through the vent and turning clockwise. The flap now stays firmly shut allowing no cold air through.

Success and heat!

Checking fuses, adjusting linkage, playing with knobs, this old girl still has heat. I just wish i spent the 30 minutes on this two months ago. duh.