Thanks Steve! I checked the values - with temp set at 74, the cabin temp fluctuates between 78-81 degrees. If I point the vent registers up towards the sensor intake the A/C starts blowing hot air out. This makes sense to me now - with the ac set to 74, the sensor thinks it's still hot inside the car, keeping the cool air blowing all the time. Point the vents up towards the roof, the sensor reads that it's too cold and blows hot air. Does this sound right?
2 X 1997 C280