Originally Posted by Excoastie
I may be totally off base here, but based on what battlerattle says... IF your evap is icing up, this could indicate a blocked drain line.
I had something similar happen on an Expedition that I used to own...
Having said that, if the truck is having the same symptoms as before, it sounds to me like something wasn't fixed correctly the first time.
good luck and keep us updated
A blocked drain wont necassarily cause icing. Though it can cause fluid retention. In my case it was simply a case of the system being over efficient and cooling below freezing at the evap. That combined with high humidity led to a complete blockage until thawed.