I see a recent question on a similar topic of intermittent heater blower problems on Chrysler.
My Cirrus '95 developed this problem this year. Mileage is about 120k
I tested the heater early in the season during a cold snap and found that the heater blower would not change the airflow from windshield to feet on the control panel dial. I tried working it back and forth but this did no good.
At my next oil chage and winter prep I took the problem to my regular service outlet. They ran the handheld codes reader or something and could not find a problem: the heater airflow switch would change the airflow normally. So I took the car and ran it. When inquiring about a repair the shop said such a repair could be affected by the 'core memory' or the control system and the repair might be in the big bucks.
Now the problem has returned. The heater blower works at the windshield and upper vents but will not switch the duct to the driver's feet.
My thought on this was: could running the codes from the dashboard tweak the electronics back into action?
Dodge Shadow, that was possible, but I cannot recall if it can be done by the owner on a Cirrus.
Please provide any solutions that are in play for this problem. Is it a switch, or sensor or that core electronics problem? Here in Wisconsin we need our heaters. ;-)