Condensation on INSIDE of windshield

[MikeNH]

AC won't engage in most any vehicle below 32 degrees as this can cause AC components to ice up. Recirc. is disabled on defrost because the air in the cab will likely be heavy with moisture from your breathing and won't clear windows well, so fresh air mode is forced. Operation-wise your truck sounds normal, but the interior fogging is absolutely an issue.

[Cloudsplitter]

Everyone's issues with moisture inside the truck cab result from several factors, but the overall humidity in the ambient outside air is the greatest factor, closely followed by rapid temp changes which cause quick condensation. I live in the South West with very dry air most of the year, but still have rapid temp changes in the morning and evening with swings as dramatic as near freezing to almost 70 within a few hours.

 

I've noticed when I lived in more humid areas of the Southern States (GA and AL, also Hawaii), older cars would start to smell from mildew. This would just happen because vehicles just cannot keep up with drying themselves out versus the high average humidity.

 

One thing I have always done whenever I leave my truck parked for extended periods (military deployments), I would get two big boxes of baking soda and stand them up on the rear cab floor. Get the boxes that have the fabric panels on the sides. This helps absorb extra moisture and/or odor. Another thing you can try is using a small dehumidifier in side the truck for several hours. Remember, a de-humidifier is like a small heater with a catch pan, so do it inside the garage if possible and don't leave it unattended or just plug it in over night.

[yamahas]

I had this happen the other day in my 2011. The cause was most likely the rain for 20 hours followed by -16 degrees Celsius the next day.

[karleepapa]

I have a 2011 Silverado and I first notice condensation on the inside of the windshield when we placed an aluminum sun protector over the dash in winter. Since not using the foil sun guard the condensation still remains. Tonight all the windows fogged up. It is cold out 30*F it has snowed a wet snow a few days ago and every time we got back into the truck the windows were heavily wet. The truck still has a new car smell, which is good, but mildew might form if this is not corrected. I am going to try a desiccant air dryer of some type. It can be purchased in packets, bags or a plug in type. I will post the results.

[mike94silverado]

I had this issue Dealer reprogrammed something it went away. I can have them look up whatever program they did when I go there tomoroow if anyone would like

[twopffenig]

I had a 2010 Sierra.It was reprogrammed, issue was dealt with.So much condensation, I was wiping off windshield to be able to drive.

[PhilB]

I would be interested in knowing what the dealer reprogrammed. I have not had the condensation problem since I started driving the truck daily. I did have the BCM updated for battery drain issues.