Chrysler Repair: Iced windows, haynes manual, grand voyager

Question
I have a 96 Grand Voyager SE Extended w/optional rear air/heat, I get no rear heat, will be attempting a rear heater core change to correct, anything else that may cause no heat in the rear? Fan blows strong, and does change from upper vents to floorboards dependant on driver temp slider. It was suggested there may be a valve that may not be opening, however I cannot find said valve in my Haynes manual (can't afford a Chilton). Also, it was suggested my recirc door may be stuck, causing it to stay in recirc, which makes sense as no audible change in airflow is heard when changing from recirc to outside air and back. My question, again due to lack of info in the manual, where is the recirc door, how can I access it, and how to I check it's operation? The recirc door was suggested as the cause for my iced up windows, mainly side glass, even with full defrost, and excellent heat from the heater.

Answer
it would be a blend air door  there is not a rec door for the rear only front. U will haft to remove the right rear trim panel and then the motors and stuff are there  Test the motor first b4 u go about removing more stuff then u need to  the heater core is more involved then U think the motor for the blend air door is easier then that.