My first question is does a defected blend door cause no heat? I'm pretty sure its my heater core too, judging by the steam and smell of antifreeze coming out of the vents... Now, did one cause the other? How the hell do I fix the blend door problem? I know how to do the heater core

 

Yes a defected blend door can cause no heat as the blend doors is what redirects the airflow to where you want the air to go. Vents, feet, defrost, etc. I had this same problem with one of our delivery vehicles last year. It was winter...freezing...and the delivery guy comes in and says "Hey man...I got the heat on full blast but its not hot" turns out it was a blend door. Blend doors are typically "Dealer Only". Typically time consuming to change as you have to tear apart the dash.

Sounds like the heater core if you are getting that sweet stench of antifreeze...smells like a leak

 

I found some revised Mopar blend doors on ebay for $50.00. I gotta take mine apart and diagnose it soon.

 

I had this issue and yes it was the Blend door and OMG it was a pain in the ****!!!