This points to resistor or climate control module.
Maybe dirty cabin filter, unless it’s normal with A.C. These models are prone to have climate control calibration issues. They are supposed to self calibrate at a set schedule, but sometimes I have to force a calibration. This may be why you have no heat. The mode door may be always in the cold position. I’ve sometimes had luck by just turning it from all the way hot to all the way cold 3 or 4 times. If that don’t work, Google climate control calibration for a 2000 Caravan and do the calibration.