Worst Window Defrost Ever

[HTX1811]

I have over 41,000 miles and the defroster and the trucks heater in general will run you out in no time.

Amount of heat is no problem. It gets plenty hot. Defrosting the windows in cold temps with high humidity is the issue.

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[DFisher]

When defrosting, you don't what to recirculate air. You have damp air trapped inside the cab from all the melted snow/ice. You're just blowing damp air back onto your windows. You need to turn off the recirculating option, or pick defrost only, to clear the windows.

 

[mtbikernate]

defrost works great. I live in a small pocket of temperate rainforest in the east. no problems whatsoever, except for the day that I left my house when it was 30F, and halfway to work the temps jumped to 44F and instantly fogged the exterior of all my windows. wipers took care of the windshield, and everything else took a few minutes for the glass to warm.

I also lived in East TX and spent a lot of time in Houston.

RECIRCULATE IS YOUR ENEMY IF YOU ARE TRYING TO ELIMINATE FOG ON THE GLASS.

You need 1 of 2 things to happen. First and foremost is that you need to cut the humidity inside the cabin. Recirculate is for keeping outside smells outside. Skunk, nasty exhaust from the vehicle in front of you, cigarette/weed smoke from other vehicles sitting at the light near you, eau de landfill (or paper plant) when you are downwind from it, etc. Recirc is also handy for keeping humidity that you exhale INSIDE the cabin. The longer you're inside exhaling, the more humidity. And so long as the glass itself is below the dew point inside the cabin (2nd thing that needs to change), that humidity will condense on the windshield.

So, your choices are to warm the glass up or to reduce the humidity inside the cabin. Warming the glass can cause other issues in the cold...especially if it's snowing. Cutting the humidity inside is a lot easier to pull off, and you don't have to constantly run the defroster on the windshield to do it.

Just need to clear the windshield right after you start the vehicle, and after that, you can direct the warm air elsewhere. So long as recirc is OFF and you're not continuously building more and more humidity inside, then you shouldn't have any trouble at all with it building back up if your hvac system is able to push warm air.

On older vehicles, I'd never turn off the A/C because the A/C does such a good job reducing the humidity when it's cold out. In my Ranger, I leave it on Auto and let the truck turn the A/C on when it thinks I need it. The Auto setting takes care of it, and does a pretty good job in the process.

Now, I have my gripes about it turning recirculate off automatically, but those gripes have nothing to do with using recirc the way you are trying.

 

[arbjosh]

Do you use the auto HVAC mode? That uses AC and heat to pull moisture and defrost.

One other thing here too. All plastics out gas. When new is when they’re at the peak for this. That transposes as a film on your glass. It is very difficult to get off with just window cleaner. There is a thread on here about cleaning glass and also dealing with your issue. Pretty sure that’s the root of your problem

What trig said. Also I put rainx on the inside of my windshield once...made it worse with the fog.

 

[THLONE]

In case you didnt get it you have a defog issue not defrost. If you keep recirculating the wet air you will get fog on your windows.

 

[KJRR]

Also I put rainx on the inside of my windshield once...made it worse with the fog.

There is a rainx anti-fog for the inside and bathrooms, glasses... works fairly well.

 

[HTX1811]

Missing the point. In cold high humidity defrost does not work well.
The recirculate when not on defrost was a side note.
The other day running defrost only with humidity at 79% or higher with the Outside temp at 29, the windows would not defrost on defrost only which does not allow for recirculate.
The following day with humidity at 65 and 30 degrees it did work.
Conclusion, high humidity and below 30 temps my defrost does not work well.

 

[Marpater]

Is it possible that the HEPA filter for the cabin needs to be change? to allow for less resistance / more air flow.
I have had on a couple of occasions the same scenario where the defrost/defog didn't seem to work very well and both those occasions were on damp cold nights, you know when mother nature isn't sure if she should snow or rain so she does both, the windshield cleared but the side windows were very slow to clear.
If I remember correctly I had to increase the temperature and use defrost only, I think I may have started with max defrost to get things started. I may have also cracked a window for a while but I am not sure on that one.
And no I never have had this issue that I recall with my Edge, F150, Lincoln in fact I think the only other vehicle that I have had this kind of issue with was my old 911, but that was expected of that beast.

 

[HTX1811]

Is it possible that the HEPA filter for the cabin needs to be change? to allow for less resistance / more air flow.
I have had on a couple of occasions the same scenario where the defrost/defog didn't seem to work very well and both those occasions were on damp cold nights, you know when mother nature isn't sure if she should snow or rain so she does both, the windshield cleared but the side windows were very slow to clear.
If I remember correctly I had to increase the temperature and use defrost only, I think I may have started with max defrost to get things started. I may have also cracked a window for a while but I am not sure on that one.
And no I never have had this issue that I recall with my Edge, F150, Lincoln in fact I think the only other vehicle that I have had this kind of issue with was my old 911, but that was expected of that beast.

I will check that. I cannot remember if I’ve ever changed it.
Thx.

 

[mtbikernate]

Missing the point. In cold high humidity defrost does not work well.
The recirculate when not on defrost was a side note.
The other day running defrost only with humidity at 79% or higher with the Outside temp at 29, the windows would not defrost on defrost only which does not allow for recirculate.
The following day with humidity at 65 and 30 degrees it did work.
Conclusion, high humidity and below 30 temps my defrost does not work well.

It does work. I live in a temperate rainforest and clear fog from my windows in cold/humid conditions all the time.

You have something else going on. Maybe it's a settings problem. Run the A/C compressor when you're trying to clear foggy windows. Maybe some other setting. Maybe it's a mechanical problem. Is there still ice/snow/frost on the windshield? That's going to cool down the glass and make it take a lot longer to clear. But the problem is NOT that the Ranger's HVAC system inherently doesn't clear fog well. It works just fine.

 

[JACKSMYDOG]

Missing the point. In cold high humidity defrost does not work well.
The recirculate when not on defrost was a side note.
The other day running defrost only with humidity at 79% or higher with the Outside temp at 29, the windows would not defrost on defrost only which does not allow for recirculate.
The following day with humidity at 65 and 30 degrees it did work.
Conclusion, high humidity and below 30 temps my defrost does not work well.

Bring it in for service, mine works great and I'm constant high humidity on the shore of Lake Erie. The only time it struggles so far has been in the thick of a storm, at -20C to keep the top corners of the windshield clear and backs of the side windows. Most days all front windows are clear within a few minutes after starting. I never use recirculate.

 

[pbethel]

Has anyone said "take it in for service" yet?

 

[HTX1811]

Has anyone said "take it in for service" yet?

LOL. Yes. I have 35,994 miles. Next stop needs to be the dealership.

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