This vehicle is the first I've owned with a heated windshield, and I love the feature. What I don't like is the lights dimming briefly when it turns on, while driving. If it's cold enough, it does this on its own, regardless if the button is pressed or not. Anyone know a fix for this? After researching it, i'm pretty sure it's the front heater making the lights dim.
Check your battery.
While on the move I haven't noticed that the heated windshield does any better defogging that a standard setup.