I doubt the auto climate controls use simple resistors like the manual systems do. It probably uses a "module" of sorts in the air duct ahead of the blower to sense air temps and make adjustments.
I would start by checking the blower motor to see if it's the problem. This should be the easiest to check by just disconnecting its plug and jumping it to a 12V source.
Good luck searching!
2007 Jeep Commander Overland - Steel Blue
5.7L Hemi + QDII
Rusty's adjustable rear UCAs
Caroline Driveline front drive shaft
285/70/17 Goodyear Wrangler Silent Armors
Activated: DRLs + Tilting Mirrors
Cobra LX 29 LE CB with Firestik antenna
Rear fog lights
Mopar Grille Guard with Rugged Ridge HID driving lights
Sylvania Silverstars Ultra hi/low
"4 wheel drive does not mean 4 wheel stop!" -Lee Goldberg, WABC TV weatherman