windshield defrost only blows center

Disclaimer: Links on this page pointing to Amazon, eBay and other sites may include affiliate code. If you click them and make a purchase, we may earn a small commission.

Dean2

Senior Member
Joined
Jun 17, 2021
Posts
2,718
Reaction score
3,941
Location
Near Edmonton
Ram Year
2021 2500
Engine
6.4
Ran defrost for half an hour today. Air temp 65 F. Truck to set to 68 F. Defrost worked perfect. Heated first and when air temp got to 73 F, cooled. All air from correct vents.
 

Brad4899

Junior Member
Joined
Sep 10, 2023
Posts
1
Reaction score
0
Location
Calgary
Ram Year
2020
Engine
Hemi 5.7
As a newbie to this forum, with a 2020 1500 Classic I was surprised at how poorly the windshield defrost worked on my Ram. After having a 07 FJ since new, I was used to windshield defrost issues with the flat FJ windshield epically with freezing rain, or fog.
My Ram consistently has issues not clearing the frost directly infront of the drivers seat, it's almost as if there is something blocking the air from the defrost vents in the windshield, as there is a inverted triangle directly in from of my face, and the passengers, so I have to lean on the center console to see when we get freezing rain. I will try this full heat and AC on trick to see if this resolves my issues.
As far as comments on OP people not active in the community, remember there are lots of silent readers who gain knowledge from those of you who are regular posters and your wisdom and troubleshooting is greatly appreciated by many of those of us who don't actively post, So thank you!
 

willtoride

Junior Member
Joined
Feb 7, 2023
Posts
4
Reaction score
3
Location
Canmore
Ram Year
2022
Engine
Hemi 5.7
Hey guys I may have something to add here. I have a 2022 Ram and it has been to the dealership 3 times to diagnose the no defrost issue. Specifically I demonstrated that when selecting front defrost only mode the air would blow out of the floor vents and only come out of the centre of the defrost vents. Didn't matter which speed the fan was or cycling through the other zones. Defrost wouldn't work properly.

I may have a solution or at least something to try. I noticed that SOMETIMES the defrost would work normally or at least it had intermittently worked, but I couldnt figure out what the common denominator was. But today I noticed it was working and the temperature was full hot. All air coming from the defrost and side window vents and nothing to the floor. I then lowered the temperature and noticed the air started coming out the floor vents!!

I have since determined, in my case anyways, that the full defrost mode will only work if at least one side of the temperature slider is full hot. Sync mode was the same. It would only go full defrost if the temperature is full hot.

I get why I couldn't get it to work other times is because usually it's in auto mode set at 21 degrees. And when switching to defrost mode I wouldn't normally change the temperature as well, It's usually blowing hot enough air in the winter. But it seemed to be consistent so far. Time will tell on more trips but it's the only thing that I've found to be repeatable and makes sense why I wouldn't have figured this out much sooner.

Put er on full hot and let me know if that doesn't do the trick.

Jason

Thanks for sharing this - I turned the heat all the way up and noticed nothing coming out of the floor vent, and the windshield defrost was working better. As soon as I turn down the heat, air starts flowing out of the floor vents again. Makes me think this is more of a software issue.
 
Top