Funky heater

[Fear2722]

Not finding much in a search so sorry if one of you smart guys have found the answer. 2003 Tahoe, digital climate control. Blows ice cold air at any temp other than 90. 90 is the only setting I get heat from. This is more annoying than anything. I've replaced the main blend door actuator.. No dice. Replaced the digital panel/display/dials and again, no dice. Hoses are hot. Thermostat is a steady 195. I left battery disconnected overnight also and still no luck. For a SUV with 123k miles... This is my only problem! Thanks on advance