My climate control would sometimes work normally,but would sometimes engage the blower speed on high and not throttle down as the cabin cooled down. This was due to a faulty "aspirator" which is in the headliner to the driver's left. This sucks in cabin air against a sensor which tells the control what the cabin temp is. Mine was reading 118 degrees,therefore the fan speed would never drop with this reading. Replacement of the aspirator fixed the problem. FYI