96 Mark VIII Why does the climate control screen hardly ever show the temp or anything for that matter but still operate perfectly fine?

Sounds like the contacts for the lighting is't making the right contact or your little lights inside the control are burnt out. - Believe it or not this is something easy to fix. Remove the unit from the dash and there is little plastic clips that hold the front display on. You can actually get at the little bulbs for replacement. Sometimes they just don't make a contact (a problem I have with mine regularly) and once you remove them and play with them a little sometimes they come back on... or just save yourself the aggravation and just go to your Ford dealer and get replacement bulbs. It's a 5 minute fix, not as big of a nightmare to remove the unit and change the bulbs as you think!