windshield has moisture on inside
My crystal ball says… with the little info you gave and no question…
most likely water is coming inside the vehicle. if you have a sunroof, check the drain tubes they might be clogged.
Or your AC drip pan tube is clogged.
If you have all-weather floor mats - the rubber type, pull them up and see if they are wet underneath. I think the above is great advice, but I have had this issue only to find I made the carpets wet, and the rubber mats prevented them from being able to dry properly. Good luck.
Hold you breathe.
or…
or, the heater core is leaking.
Is the moisture somewhat oily?
If you have the HVAC system in recirculate mode, moisture will build up and condense on the windshield, particularly in cold weather.
Is the film slippery like oil?
I couldn’t have said it better myself!
No, the AC operates when in defrost to dehumidify the air.
NYBo is right. If its in Recirc, little fresh air comes in. The damp interior air just keeps moving around inside.
In cold winter weather I used to see to see some cars with frost frozen on the insides of the windows. I surmise those folks were in Recirc most of the time, and the moisture just stayed inside. Between people kicking snow off their shoes in the car, and simply breathing, a lot of moisture builds up. In very cold weather, once the interior warms up some of that ends up in the air and then freezes on the cold windows.
Knowing this, Chrysler engineers made it so my 2007 Town and Country’s HVAC system will not run in Recirc when I turn on AC and/or Defrost. And if I have set it on Recirc, the next time I start the car the HVAC is in Fresh. I expect many or most carmakers by now have also idiot-proofed their HVAC systems in some way.
Not necessarily. If it’s too cold, the compressor won’t engage, and, in some vehicles, you have to hit a button to activate the A/C.
in some of the vehicles I have experienced, the a/c compressor comes on when you select Defrost, even if the a/c button is off.
Yep, cars I’ve driven recently all have the a/c on when the defrost is on, recirc or not.
I believe that a quick change of weather can cause this. Just saw it on my car. We had damp weather warm for the season and in the evening the temp dropped 30 or so degrees. Frost one time and another little droplets of water.