Cabin Temperature Control Issues?

[AndrewF]

2024 WT with base climate control.  I've had this occur a couple times now that when the blower is on cold fan (no AC, just fan) it will start blowing hot air.  Yesterday i noticed while the truck was outside idling on grass while i was hooking up a trailer the cabin got very hot and the system was blowing hot air. Outside temp was low to mid 60s. Changing the temp knob back and forth didn't seem to do anything, but once i cycled the AC on/off it seemed to improve back to normal. 

 

It is hard to recreate the issue but it does appear that when the truck idles at a stop the system starts to generally blow warmer air, and once moving again temp decreases.  I'll have to pay attention whether this issue only occurs when at a stop or moving as well. 

 

Is the air intake on these trucks in a place that it sucks a lot of hot engine compartment air?  I haven't noticed an issue like this with any other truck/vehicle I've owned but sometimes that is what appears to be occurring.

 

 

[Crazy Canuck]

Vehicles generally draw air from the cowl area by the windshield.  If you have it to full cold but are not running the A/C, it will be unheated (by the heater core), outside air.  If the air around the cowl heats up from idling in place for example, you will get air that is that temp.  When you cycle the A/C, it removes the heat from the air.  Driving blows higher volumes of fresh air by the cowl so you get back to relatively outside temps.

[UltimateToolReviews]

AC is low on freon and/or a senor is going bad, I did a whole thread on this issue on my 2022, sounds exactly like what you have. 

[AndrewF]

38 minutes ago, UltimateToolReviews said:

AC is low on freon and/or a senor is going bad, I did a whole thread on this issue on my 2022, sounds exactly like what you have. 

Unfortunately this is when the AC is off and only cool vent so I don’t think Freon is the issue. But I am curious about the sensor part so I will have to check that out still. 

[UltimateToolReviews]

On 10/7/2025 at 5:38 PM, AndrewF said:

Unfortunately this is when the AC is off and only cool vent so I don’t think Freon is the issue. But I am curious about the sensor part so I will have to check that out still. 

Ah ok, then that's probably a bad vent door inside the dash or something.