1999 Oldsmobile Intrigue HVAC Problems Dual Thermostat Control

Hello,
Thanks for the help. I have a curious situation with my 99 oldsmobile intrigue. In the summer time the Dual Thermostat (DT) blows hot air. In the winter time, it simply blows cold. Even putting the control on 90, it simply engages the AC compressor and blows cold air. It's almost like electrical like the computer is "confusing" outside (external) temperature with cabin desired temp. Any ideas?

Thanks!