Here is a question, for any one out there who could help. On my 96 Mark VIII climate control there is a problem which the dealer say
it will coast me about $600.00 to fix, I didn't take my Mark VIII in, I just talk to the dealer on the phone and explain the problem, so
now I'm going to explain what's going on, when I try to use my A/C or better yet, when I use my A/C it only blow hot air out the vent,
but a while back before the constant hot air, my A/C was working then it change to hot air and change back cold air, it will do that
from time to time and then other time it will stay hot I will stop my car go do what ever I went to do, come back start my Mark VIII the
A/C will work for a while and then change over to hot air and stay on hot, and now it will not even blow cold air I know my
compressor is working fine because I lift the hood and check the A/C line and they are very cold almost to cold to touch, I believe it my climate control and the reason I say that because the number on the climate control panel flicker back and fourth between C and
F, so I went ahead and order a climate control hoping it's the control. I hope that I'm correct with my fingers tightly cross.

any opinion

Probably not the control head unit. It sounds like the blend door to me.
Here's an article:

http://mark8.org/lod/blend_door_repair.htm