Post by
kerrton »
https://forums.nicoclub.com/kerrton-u88348.html
Fri Jan 29, 2010 6:50 am
If you have consistent, cold dry conditions this shouldn't happen, but if you have fluctuating temperatures, lots of moisture being brought into the vehicle then this can happen. If you give us a little more info. I think we can determine if you have a problem or not.
Do you have the frost on the inside of the windshield too, or just the sun roof? If it's just occuring on the sunroof and the windshielf and side windows are completely clear, then you may have a seal problem with that sunroof.
If you get day/night temps that straddle the freezing mark, this can also be a cause. When the temp is warmer during the day, above freezing, this causes the air to hold more moisture. If you trap that warm moist air inside the vehicle and the temp drops significantly to below freezing overnight, you come out in the morning and the inside of your windshield can be frosted over. This is even more of a problem if you bring excess moisture into the vehicle, such as snow on boots, and a car full of sweaty kids after sledding or skiing will really crank the moisture level up!
Let us know, I think the most relevant thing to check is if the frost is localized to just the sun roof. If so, it's probably not sealing properly.