Alright, I've kinda looked around, and I'm not really seeing this coming up on searches, so here's a thread on it.

We've finally hit the winter cold snap and it, as usual has revealed some issues that the summer heat has covered up.

It seems that when I get the truck warmed up, I can turn on either the front vent setting or the recirculate setting, and get heat that will almost run you out of the cab. The problem is is feet and defrost. When turned to either of those settings, the "heat" feels more like you have the AC on, but not quite.

I don't suspect heater core as it isn't leaking and the heat on the recirc is great.

Thoughts?

 

Sounds like one of your mixture gates isn't closing/opening fully. I don't know the full cure, but I've read threads about it before.

 

AH! That's what I was forgetting. Blend doors. Damn, that slipped my mind.

 

Noice!