Ice on windshield interior

When the temp reaches below freezing, my interior windshield is covered with ice. Why is this happening and what can I do to remedy it? Any help will be appreciated!

Turn the switch to bring in fresh air NOT recycle. Keep the defroster on high with high heat.

Yes. I do what you suggested and eventually it dissapates but why is it happening and how can I keep it from doing so? Thanks for responding!

You may have to open the window and leave the defrost on high until the heat starts flowing. Also if you are sitting close to the windscreen or if there are a lot of people in a small car or if you clothing is damp, it will be worse.

Many thanks for responding. Does anyone know why this happens and how I can fix the problem?

You have too much moisture in the car…eg. bringing snow in on your boots etc. dry out the mats, air out the interior by keeping windows open, run air conditioner with defroster to remove frost and keep fresh air vents open…the problem will self correct over time.

I’m not sure I can run the AC, defroster and fresh air simultaneously. Running the AC(cold air) would just exacerbate the problem.

air conditioned air is dehumidified…my RAV has a defrost setting that automatically sets AC on. I don’t know why you can’t run all at once.

A/C doesn’t cool the air, it dries it. When the defroster is on, the A/C cycles automatically, but running it constantly for about 15 minutes or so once a week will keep the interior dry. In fact, most, if not all, manufacturers recommend running the A/C for about 15 minutes every couple of weeks all year to keep the seals and everything else in the system lubricated and working, so that come summertime, you can get cool, dry air.

So, in short, run the A/C with the defroster on will fresh air (you can do it) and your interior ice problems will be gone.

Thanks for your help and clarifying!! I’ll try it. Should windows be up or down? The temp is plummeting here and isn’t going above 20 tomorrow. Thanks again!

I don’t belived anyone told you to put the temperature control on “high” at the same time as you run the defroster. Some cars automatically turn on the AC when the defroster is operating. Others require the driver to manually turn on the AC. It’s true, AC removes the humidity from the air. The heat warms up the air. When the warm, dry air hits your windshield it’ll remove the ice, fog, mist, etc.

You live in Eastern Ontario? Cause that’s the temperature here right now.

By the way, my windows were frozen up this morning after work. 5 minutes with the A/C on (and windows closed - no blanking way I’d drive with the windows open in this weather!) and the windows were cleared right up.

Try putting the “mode” setting not on defrost when you park your car. The 3 “modes” are defrost, dash, (same as “vent”), and floor. If the heater/AC system is on defrost when you get out of your relatively warm car, the H2O in the system will evaporate/linger up to the windshield and freeze to it. Do the other rccomendations stated above, too. Let us know what results are. Most OP’ers never post back.

Thanks for responding. If not on defrost, should the mode be dash or floor? What is an op?

I live in NY state where it’s currently 12 degrees.

My guess would be floor, since it’s furthest away from the windshield. To me “OP” means Original Post as opposed to our posts. OP’er means Original Poster- you in this case. Everyone has different abreviaions, though. If you peruse this board you’ll find that

posters give the Original Poster advice, and then that’s it- you never find out if your advice solved the problem. You seem to be an exception to the rule. Anyways, let us know what pans out.

Thanks for clarifying. Please explain about the car floor. Thanks again.

I’m just guessing that if the mode setting is left on “floor”, then the evaporating water in the system can’t linger through the defroster vents or the dash vents which are closer to the windshield than the floor vents. I live in SE Pa, where it’s probably warmer in winter than where you live, and we get ice on the outside of the windshield pretty often in the winter; not too often on the inside of the windshield

glass though. During warm, damp weather, though, I’ve seen drops of water all over the inside surface of the windshield in the morning. The drops were concentrated exactly where the defroster vents pointed to the windshield glass, and in these cases the mode had been left on defrost. When I then developed the habit of putting the mode on floor when I got out of my car at night the symptoms disapeared. That’s

similar to your scenario except of course that the drops/liquid are frozen due to the extreme low temperature.

Are you saying I should run the defroster on the floor?

Oh… sorry… :slight_smile: