It is cool here now in MN and when I turn my heater on (blower speed 1-4) I can hear the A/C clutch cycling on and off. No other buttons are on or being pushed to get this to happen. Whats the deal? 2013 Subaru Forester
Most cars do in those two selections on the dial. All 7 of my Subarus over the years have. They figure if you need to send air to the windshield, dry air will defog or defrost it faster.
Personally, it bugs me, so I disable it. The method varies over the years. In earlier years, it was as simple as unplugging the lead to the switch that activates it. On my 2016, I had to pull the HVAC controls completely apart and gut a tiny microswitch on the circuit board.
While it might annoy you (having the AC run in defrost mode), not only does the AC dried air clear up your fogged windshield, cycling the AC also allows refrigerant and lubricants cycled through the system in the winter time, so the seals don't dry out and fail.