ACC - Only high
 

1985 300TDT - Climate control only gives high setting - cold. Through vents at windshield top - all the time. It will split air to lower - footwell if button is pressed. New ACC unit?? Also - NO HEAT through vents even if wheel truned all the way warm. Sometimes though - it feels as if warm air is seeping out of dash round vents. - slowly. Thanks

Probably is the CCUnit. When mine failed it would adjust temp but the A/C compressor was on 100% of the time, regardless of button pushed. I lived with that for months but then one day it went to full hot and a day later smoke started to come out of the unit. (I guess it decided I couldn't take a hint). I later discovered my circulation pump was frozen and may have shorted the CCU so you may want to check that too. There are a few places you can send your CCU unit to where they will check it. If you need a new one definitely go the rebuilt route because it's much cheaper than new.