Temps in my area are getting down to minus 15 in the morning and that is when I have problems with the windshield fogging and freezing on the inside after I take off. The defrost motor just won't keep up at that temp and the angle of the windscreen hitting that cold air makes it hard to thaw out.

I solved the problem by filling up a tube sock with Non clumping cat litter and laying it on the dash. It absorbs any vapor in your cab from breathing and keeps your windscreen fog free.

 

Minus 30 here today never had a problem. Is your blower motor full of leaves amd maybe not blowing full on? Or maybe a blend door is jammed and not directing air to windshield. Live in northern Canada where it is regularly very cold and I’ve never had a problem, the heater works quite well in the d2

 

A/C will do it too

 

Blower works fine. Its more of a matter of water vapor in the cab when driving from snow getting tracked in and vapor in breathing. I park outside in blowing snow so I cant just crack the window when I get home. Its not fog. Its a layer of ice on the inside that forms up in the first 5 miles after I get rolling and the air hitting the screens freezes it. I am planning to go to the heated windscreen next year. The cat litter trick works great. I got the idea from this news story. Its funny.

https://www.huffpost.com/entry/man-j...b03c8a02d3b52f

 

The heated windshield is pretty underwhelming, I wouldn't bother with that upgrade unless it's next to free