During the spring season lately my windshield has been fogging up badly. Usually at night when headlights glare off of the fogged up surface. I cant figure it out. I 'll run hot defrost, cold defrost, windows up windows down, heat, and vent, nothing works. I noticed something this morning aswell, I had it on cold defrost and I saw smoke coming out of the vents. AS soon as I saw this I shut off the blower and turned the setting to off. When I tried it again everything functioned normal with no smoke appearing. The blower pushes the air well and the heat works fine so what could be my problem? I'm tired of having to wipe down the inside of my windshield at every red light. thanks for any help or suggestions on where to start.