Hi. You may be complaining about something that is "by design" and not a problem. All vehicle manufacturers have a feature implemented into there climate control system. This feature helps the A/C compressor last longer. In the warmer seasons the A/C is used but in the colder seasons the heat is used. If the A/C compressor isn't used for a while the seals can harden and leak. To keep the seals pliable the A/C compressor is activated when the defroster is used. We don't keep the defroster on. After the windshield is warmed then we switch the vent position. This action prolongs the life of your A/C compressor. Any questions please write back. Good Luck.