Alright I have done some searching and haven't found much help. I have a 2000 tahoe LT 5.3L motor with computer controlled climate control (Not Dual Zone). I have noticed that the heat coming from the front heater to be not so great. I have checked the inlet and outlet temps of the heater core and they were both setting right at 168 Degrees. The duct temp at idle in a shop was 120-130 ish. We turned the ac on and it went to 60 degrees. We turned it back to hot and it very slowly got hotter up to 120 degrees. We have done the recalibration of the door actuators by using the fuses. We had the high dollar Snap On scanner that looks like a tablet and it would access the Climate control (option not available that year). The blend door motor does move but not the full range. I unbolted it and moved it by hand. It was free of obstruction and opened all the way and closed all the way. The actuator in question is the one almost directly behind the center console. I even replaced it to try that and no difference. Any ideas whats next the control panel or another unknown door actuator? Thanks for any help.