Why does AC fog the windows in my car instead of clearing them?

When your defrost or AC makes your windows foggy instead of clear on cold Ann Arbor mornings, it usually means the system is not dehumidifying the air properly. Low refrigerant, a weak compressor, or a blend door problem can keep moist cabin air from drying out, so condensation forms on the cool glass instead of disappearing.

On Michigan winter and shoulder‑season days, wet boots, jackets, and slush tracked into the car add moisture that the HVAC system must remove. If the AC side of the system is weak, the defroster blows warm, damp air, so the windows fog and can even re‑fog while you drive.

Hoover Street Auto Repair can test your AC/defrost performance, check system pressures and airflow, and restore proper de-humidification so your windshield clears quickly on icy, humid Ann Arbor mornings.