Gladiator blowing cold air on cold start-up, fan not adjusting

[ShadowsPapa]

My 2020 has done this since I bought it used.
All manual hvac,
sometimes,very randomly,
On first cold start up, the fan will blow full force, on defrost for about 45-70 seconds.
All the turn dials do nothing during this time.. cannot control fan speed,temp or change where the air is blowing.
Ive been told this is a safety feature bc the hvac module has lost communication with the main module. Ive heard there is a tdc for this but I am out of warranty so it would cost $150-300 to diagnose.

That's a different thing than the later models are doing.

Ours isn't full force for a few seconds.

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[Antrmo]

Ohh ok, sorry sounded very similar

 

[legacy_etu]

@legacy_etu - thanks, just like my 2020 is. I'm going to take my wife's 24 Wrangler out tonight and see how it does.

One thing I just thought of, if I remote start and open the door the fans are blasting full speed. Only when I jump in and hit the start button does the fan slow down to nothing until the engine warms.

If I just jump in without remote starting and hit the start button, then the fans are basically off until the engine warms.

Al little nuance there but you didn't say you were remote starting so this didn't occur to me initially.

 

[ShadowsPapa]

If I just jump in without remote starting and hit the start button, then the fans are basically off until the engine warms.

on my 2025, the fan is running - not on high like with a remote start, but at least a couple notches higher than my prior JTs did.
It's annoying, cold or cool air, and the sound of the fan, before the thing is even moving.

I understood the fan on full with remote starts - made sense, no one in it, might need some defrost help, no one to annoy in the vehicle.

I really liked the "no fan until there's something warmer than the air in the cabin to circulate - totally makes sense. Why run a fan to transfer heat from a heater core that has COLD coolant in it. Wait until we can supply some warmer air to raise the cabin temperature.

I don't get the "let's run the fan on medium and blow some cold air around" when there's no heat to extract from the heater core.

 

[legacy_etu]

on my 2025, the fan is running - not on high like with a remote start, but at least a couple notches higher than my prior JTs did.
It's annoying, cold or cool air, and the sound of the fan, before the thing is even moving.

I understood the fan on full with remote starts - made sense, no one in it, might need some defrost help, no one to annoy in the vehicle.

I really liked the "no fan until there's something warmer than the air in the cabin to circulate - totally makes sense. Why run a fan to transfer heat from a heater core that has COLD coolant in it. Wait until we can supply some warmer air to raise the cabin temperature.

I don't get the "let's run the fan on medium and blow some cold air around" when there's no heat to extract from the heater core.

Yeah, we're together on thinking how this should behave.

I just wanted to add in my experience with remote starting in case that was it.

 

[Coltron_Actual]

My '25 Mojave is behaving this way also with remote starts. Ice cold air with a lot more fan than it would use otherwise. My '21 JLUR did not behave this way at all. I thought it was just because the little turbo engine heated up so much faster, but nope seems like a fun new feature.

I'm getting in and turning off the HVAC until I drive for a little while. At least it's not as bad as waiting for a 4.0L to get fluids above room temperature.

 

[Y-Guy]

I've been testing in the mornings and as @ShadowsPapa described its a low blowing fan but not as low as my previous 2020 was, but not as hard as the fan on while using remote start. I've been trying to swing by the local dealership to talk with service tech, but work has been keeping me busy.

 

[Gvsukids]

One thing I just thought of, if I remote start and open the door the fans are blasting full speed. Only when I jump in and hit the start button does the fan slow down to nothing until the engine warms.

If I just jump in without remote starting and hit the start button, then the fans are basically off until the engine warms.

Al little nuance there but you didn't say you were remote starting so this didn't occur to me initially.

That's to help defrost the windshield and quickly warm up the Jeep.

 

[ShadowsPapa]

That's to help defrost the windshield and quickly warm up the Jeep.

Yes, and we accept that as normal for remote start.

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