Relentless window fog in rain

Hello! I have an issue where whenever it rains every window in the truck fogs up to the point where I have to run the windshield defrost on full blast just to drive.
The rear window and the rear passenger windows are fogged up 100% of the time in the rain, nothing I do fixes it.
Dying for help here cause it makes it almost impossible to see.
Thanks in advance!

 

Where do you live?
Outside temp?
AC on?
Heat on?
This just started?
Or did you just get the truck?

 

Canada
6°
A/C broken
Heat or Cold doesn’t seem to make a difference
Always happened
Had truck for 2 years

 

A/C is the issue. It acts as a dehumidifier if it's on with either heat or defog

 

This is your issue. The defrost system uses the AC to dry the incoming air.

 

1. The effect A/C has on defrosting your windshield

Your car’s defroster is tied into the air conditioning system. While that means it can get quite warm and very cold, it also means something else. If you’ve ever had to use a humidifier in your home during the winter because your furnace was removing too much moisture from the air, you’re already familiar with what’s going on here.

Your air conditioner (whether it’s set to cold or hot) condenses the moisture out of the air into water. This condensation is vented through a drain hose that runs from behind your glove box out the bottom of the car. The system then pumps dry air into the car. When you turn on the defroster, it pumps dry air up toward the windshield. This helps to evaporate the moisture.


cut copy paste off the googles

 

I bet the problem is a broken blend door actuator

 

Yikes! Totally different weather conditions than mine.
But the other posters are correct. You need that AC to run to remove the humidity.

 

Sounds like you’ve got a leak and water is making its way into the cab.

AC helps defrost for sure but it isn’t critical. I’ve owned several cars with no AC or broken AC and they all defrosted just fine.

 

The A/C is engaged automatically in demist mode, even if you don't press the A/C button.

Canadian falls/winters tend to have high humidity. You need to get A/C back running.

 

Mine is similar. Whenever there is water vapor in the air (rain, snow, fog, low dew point) my windows fog up almost immediately. Which sucks because that’s 9/10 months of the year here. I have accepted that I need to run defrost when these conditions exists. Have not had this issue with other trucks I have owned including two other non Tacoma Toyota trucks.
My ac works fine.

 

Make sure your re-circ isn't on. Check that it changes when you hit the button as the little orange indicator light may not be working.

 

^^^ This.

That "Recirc" button on a Toyota could easily have been named "Condense" as that more accurately describes its function. I dated a girl years ago who was determined to use it to feel warmer quicker. I don't think she did, but she *always* complained about her Corolla misting up inside. I was never able to convince her to stop doing that.

In fact, she'd do it in MY car when I wasn't looking, for the same reason. And then I'd be trying to figure out why my car windscreen was all condensate inside.

Without trying to sound (too) sexist, is there a woman involved here? I hope you have better luck than I did...

 

I also find if my windows haven't been cleaned in a while and have lots of fingerprints or that film that accumulates up over time will make the fog worse. And make it slower to get rid of.

 

Check out your local sports store. Look for dive mask anti fog. Can also be found at opticians office and camera stores.

 

Just a question, how often are you touching your windshield?

 

Not me, the wife and kids

 

I was gravitating towards the broken AC contributing to the problem, but the other thing that jumps into mind is- possibly a leaking heater core? It will coat the inside of a windshield quickly and NOTHING will keep the fog/condensation away. Check the coolant level to see if it's filled then go from there.

 

Could also try RainX on the inside of the windows.

 

Unti you can get your AC fixed, it might work to put a bucket of this inside the truck.

https://www.canadiantire.ca/en/pdp/...y-moisture-absorber-4-lb-bucket-0409737p.html