Its going to be your mode 2 door. which is barried underneath your dash, a lot of screws, and a metal plate that you may need to cut to change the door.
I just about took apart my whole dash, when i decided it was not a winter job and I would just deal with it lol.
I did mess with the mode 2 door motor and linkage and it seemed to have made a diff. I do have heat to my side now, but I only get heat on full fan, so maybe if you have a garage or somewhere warm to tackle it, you might be able to do the same thing. i'd rather adjust the temp then not have heat at all, or crack a window (i'm a smoker so thats usually happening anyways lol)
there is a few other threads on this. one has links to videos on what to do for where you godda start to tear apart the dash. i'll try to remember to post them here for you to look at