I have to agree that the windshield clearing of both fog on the inside and snow/ice on the outside is lacking for such a seemingly well designed vehicle. I have had the same situation as you with ice on the windshield but did find that on high defrost it would keep it clear. Didn't cook myself out of the vehicle yet though...

 

I used aquapel. It doesn't allow the ice to build up. It is a DIY chemical treatment that makes your windshield very slippery kinda like rain-x, but WAY better.

 

Did you have the a/c on with recirculation set to "off?" That combination is the best way to reduce fogging/icing without making the interior uncomfortably hot.

 

I often get -20, -30 Degrees Celcius, and yes, the windshield defrosting while driving it quite poor, as is the heat in the footwells. My feet are always colder than the rest of my body in my TH.

 

We drove through a winter storm for several hours the other day with our rental Sport model in the mountains of Colorado with the temperatures varying from zero to minus 10 fahrenheit. Toecutter is correct...what works best is AC on and recirc off. To keep ice from forming on the windshield, we had to crank up the heat and fan all the way, and send all the air to the windshield to keep the windshield as warm as possible. But it did make the interior unbearably hot after a while, so we opened the front passenger windows about an inch to get rid of some of the heat. Worked reasonably well considering the severe conditions. I also needed to keep turning on the rear window defogger as it "times out". I needed to keep the rear glass heated. If I did not, the rear wiper was useless.

 

Chrysler makes a heated windshield washer fluid accessory, maybe look into that?

 

You can ask the A/C compressor to come on all you want, but the fact is at 32F/0C, the compressor will not engage. Also any time defrost or defrost/floor heat is chosen, the system automatically de-faults to fresh air. For the conditions the OP was describing, I don't think there was really a problem, as I think any vehicle in those conditions would have had a problem keeping the windshield clear.

 

.... Also any time defrost or defrost/floor heat is chosen, the system automatically de-faults to fresh air. ....

Thanks for dropping these little tidbits that are often not in the owners manual!:smile:

 

i agree the defrost system in my TH sucks.
Even at what I would call warmer temps it has to be on full and like many are saying gets the cab very, very warm.
My diesel once warmed up on the highway keeps the windows clear better than the TH.
On the side it is -39C without a windchill here this morning and supposed to be this way for the rest of the week.

 

Are there any owners from Winterpeg that could chime in? From my memories there it was usually around -30C, so if they don't have problems, they may be doing something properly or differently.

 

Where I live is a lot colder than Winnipeg. I am about 6 hours north of Edmonton. I do have a problem with keeping all of the windows clear in the winter on my TH. Just hauled water with my Diesel for about 3 hours and the windows all stayed clear. It is near -40 here today. The TH today would be very frosty on the windows, especially the side ones.

 

Hit the defrost button with the A/C on, recirc off, and if it gets too hot then turn down the temperature setting.

On Wednesday night I drove home from the airport with the thermometer reading -1F. Defroster with A/C on, recirc off, and set the temp to 67F. It worked great and was a comfortable cabin temp.

 

I have to super heat my windshield as well. I just crack a window or two and let the vent shades keep the weather out.

 

No doubt most of you that live in cold weather climes know that this issue is not unique to the Cherokee. Keeping the windshield as warm as possible, and venting excess heat out the windows is a tactic I learned many vehicles ago.

 

We experienced very low temps (3 degrees)

3 degrees?! I wish it were 3 degrees here! Its been -35 here for the past few days, with a wind chill of -47.

I haven't had any problems with my windows icing/fogging up. I usually keep it set to blow air at the window and the floor, and I adjust the temperature to my comfort.

 

I think the key is that you need dry air blowing across the glass to remove moisture. It doesn't necessarily need to be scorching hot. If the cabin feels too hot then you can turn down the temperature setting and increase the blower fan speed. I'm getting repetitive, but to get dry air you need the A/C on and the recirc off.

 

Cold air can contain less water vapour the colder it is.
Hot air can contain more water vapour the warmer it is.

You won't fully saturate dry air by blowing it once over your frosted windshield, etc. But you will remove more with dry air.

So yes, you are correct. Hotter air will melt ice. Drier air will defrost or defog more quickly.

 

If youi have rain sensitive wipers you are NOT to use such chemicals.

 

Indeed. They can interfere with the rain sensor.

 

Thanks for the reminder about the A/C. My pickup actually turns on the A/C when the system is on defrost and it keeps the windshield clear in all conditions. I had forgotten about that detail.

 

Other things I thought of since my last post:

Any excess moisture inside the cabin (e.g., snow or standing water on your floormats, several sweaty passengers after a day of skiing) will make fogging more of a problem.

If you park inside a garage and there is snow or water inside your vehicle, then leave the windows and rear hatch open all night so moisture can exit the cabin.

 

Glad I came across this thread. Didn't know if it was unique to me, but I have more issues with defrost with this jeep than ever with any other vehicle. Thought it was pretty embarrassing the way it struggles to clear interior fog and/or exterior ice. Will try out AC to see if that helps.

 

Do the windshield defroster lines help at all?

 

No. My TH performs poorly compared to previous vehicles as far as windshield icing is concerned. Haven't had a problem with clearing windshield fog though . . .

 

When on my last trip to Colorado from Arkansas I saw temperatures across Kansas as low as -8. I only had one issue with ice on the front windshield and that was after skiing with the temperature at -4 the next morning. The moisture in the floorboards was frozen and the warmer the interior got the more moist it got, no way I was rolling down any windows. I kicked the hawk over to manual and set it to the front defrost with the AC on. I have the cold weather package which warmed my windshield up about 2 inches from the bottom almost instantly clearing ice and snow, the rest soon followed. The rear glass also cleared very quickly but I had to engage the button several times due to the time out feature. The side mirrors also cleared themselves quickly. The cold weather package was well worth the investment. My feet were in boots with wool socks so I guess I've never noticed the lack of circulation that is complained about in the floorboard heat setting. Being from Arkansas, my only mistake on the trip was not having the "good" antifreeze windshield treatment in the tank, it was frozen any time temps got below 15.