Chrysler Repair: 04 pacifica 3.5L: HVAC ATC control frozen, automatic temperature control, temperature control unit

Question
My digital display of my dual temp controller above the radio is no more illuminated.  It is now froze on the last setting that it was on. I cannot change it at all. Its froze on a/c and will not change to heat at all.  Could it be a sensor or the whole display? Is there any way that I can bypass the a/c without the display just so the heat will work for this cold weather? Please help.

Answer
Hi Marc,
There are a couple of approaches: first check fuses 45 and 50* in the power module in the engine compartment as that powers the controls. The manual suggests that there is a manual override option but I haven't found that yet. Have you checked the owners manual section for the Automatic Temperature Control Unit for that option? Try pressing the Auto Hi and Auto Lo buttons to see if that causes any change.
The whole body wiring system is computerized and trouble-shot by an expensive diagnostic readout box available only at a dealer such that without being there and plugging in the device I am very limited on exactly what is wrong. The DRB readout box will presumably give a single phrase analysis which then can be expanded upon by referencing to the manual, but without that phrase I don't know where to begin. Nothing along the line of being frozen in one setting is shown. However if all the other illumination is gone, I would certainly start with the fuses.
Good luck and please let me know of any progress you make via a follow-up question.
Roland
* Fuse 50 is in front right corner group of 5 fuses, the rear-most one; 45 is at the very rear of the box, right one of the pair of fuses there.