Insde winshield fogs up

Is the heater control in the defrost position? Most cars will automatically turn the air conditioning compressor on when defrost is selected to dehumidify the air being directed on the windshield. This keeps the windshield from fogging up, and helps defog the windshield more quickly if it is already fogged up.

Hi Brad, Did your windshield Fog up immediately when you switched to defrost? Can you also feel air coming from the vents at the top in defrost mode? If so, Could be your heater core is leaking.....If not I'm going to need some more information. Hope this helps, Good Luck, Randy.

I’m happy to assist further over the phone at https://www.6ya.com/expert/randall_d932ef6e01588b0f

There may be a leak in your heater core inside of the care. This would cause moisture to be blown up onto the windshield.
Take the car to a mechanic to verify this.

Is it fogging up when you use the heat or a/c? Is it fogging up after sitting outside on a particularly dewey night?

An easy fix and one to try first is turning the temperature gauge over toward heat, and setting the directional controls to defrost. Up the power on the blower for a moment. The warmer air will usually clear up a foggy windshield in seconds on a chilly or even not-so-chilly morning. The condensation on the glass needs a change of temp in order to evaporate. Sometimes you can get the same effect by using outside air to circulate through your car's blower system. Most have a way of circulating either inside-car air, or outside-car air.

If the glass fogs when you're driving down the road and have the heat on, or the a/c - do you smell something sweet or see white smoke coming out of your air vents? If so, you could have a faulty heater core. I wouldn't imagine this is the problem on such a new vehicle, but it could still malfunction.

Of course, if you're trying to wipe this fog clean and it won't go away, maybe you've got someone smoking in the car and leaving a film on the glass. It would take a lot of smoking to make the windshield look foggy though.
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This is speculation, but the fogged windshield, the noise behind the dash, and the temperature gauge actions lead me to the heater core. When they develop any leak they fog the windshield, and enough fluid loss or an air pocket could explain the temp gauge readings.

Check your coolant level, if its low it may indicate a heater core leak into the vehicle interior. It will severely fog up the windshield and seem like an oily deposit on the glass. If good just keep the heater on defrost to the windshield or blend to defrost and heater.

HI,
I think you are experiencing normal condensation,
try putting the heat and AC control to the position that blows a small amount of conditioned air up through the defrosters. This dries the windshield.
Good Luck !!!!!!!!!!!!

The hot and cold difference gives you that, usually in the morning, you can clean the windshield inside and apply Rainx Anti-fog here's the link to what it looks like, you can get it at Autozone Pepboys etc.
http://www.amazon.com/gp/product/B0009H5W66

If you can feel the air from the blower motor blowing up on the windshield it is probably one of two things. Either your heater core has a leak and the anti-freeze mist film is all over the windows or your heater control valve is not working.
Does the heater get hot or can you feel hot air on the windshield? If so your heater core is probably leaking and making steam inside your car.

Sounds like your heater core is bad. Have someone check out the heating system and possibly replace heater core.. that should take care of the fog problem also by enabling you to use the defrost... Good Luck!