Heater/AC blowing hot air at 60 or higher

[ShadowsPapa]

UPDATE - it was SO humid for a while today the evaporator in my WJ frosted up - when I parked it in the garage it thawed and WOW the huge puddle on the floor actually ran across the floor and to the walls (instead of to the drain, of course, which was 2 feet from the Jeep)
I bet it was 2 cups of water at least after I shut it off and it thawed.
WOW.
So - does a Gladiator run a defrost cycle?

Sponsored

 

[mr_bots]

The only car that might have a "defrost cycle" would be the Tesla Model Y because it has a heat pump. Other vehicles just have a cycling or variable speed compressor with a pressure sensor in the system to prevent freezing. If your A/C freezes up in the summer there's something out of wack in system usually low on refrigerant.

 

[ShadowsPapa]

The only car that might have a "defrost cycle" would be the Tesla Model Y because it has a heat pump. Other vehicles just have a cycling or variable speed compressor with a pressure sensor in the system to prevent freezing. If your A/C freezes up in the summer there's something out of wack in system usually low on refrigerant.

That was my thought on the WJ - I bet it's low. Heck, 16 years old, 126,000 miles, not best care in the world before my father bought it (and then what did he know of AC and such? Nothing)
I still have all my AC stuff so I'll check it out now that our weather is no longer 10+ degrees over normal every day.

 

[Gagoatroaper]

Just took delivery of our 2020 Gladiator last week and absolutely love it!

Has anyone had issues with hot air blowing out at settings of 60 or higher? If we bring it to Low and begin feeling cooler air and then increase to 65 it's fine for a moment. Then, hot air begins to blow and it feels the same if we have it set at 65 or 80.

Dealer looked at it and told us no codes showed up when analyzing and that there have been no issues reported, however this doesn't seem right. They recommended we drive it for a bit and see what happens.

Any thoughts on this would be appreciated. Thanks!

I have a 2020 gladiator sportS and on hot days, humidity appears to be a factor, with AC temp set just above the max AC setting, about every 45 minutes the heat comes ouf of the floor vents for a few seconds, cab gets warmer and humid, then AC goes back to working find. This cycle will occur every 40 minutes or so.

 

[ShadowsPapa]

I have a 2020 gladiator sportS and on hot days, humidity appears to be a factor, with AC temp set just above the max AC setting, about every 45 minutes the heat comes ouf of the floor vents for a few seconds, cab gets warmer and humid, then AC goes back to working find. This cycle will occur every 40 minutes or so.

Yup. Would depend on your temp setting. I bet i was right about a defrost.....

 

[MrZappo]

Yup. Would depend on your temp setting. I bet i was right about a defrost.....

Its either a defrost or maybe some means to put "fresh air" into the cabin on some sort of cadence ?

Which would be funny as jeeps aint exactly hermetically sealed things ...

Either way,. if it happens on a schedule it is the computer doing it ... And if that is the case, then someone wrote that code to serve some (believed to be) logical reason ... I cant for the life of me figure out what that might be though ....

At face value, it does not seem necessary or reasonable .... So either it is just a bad error or there is some reason we are unaware of ... Defrost cycle seems to make some sort of sense ... But then I have to ask, why is this the only vehicle in my life or memory that has needed it ???

 

[ShadowsPapa]

Its either a defrost or maybe some means to put "fresh air" into the cabin on some sort of cadence ?

Which would be funny as jeeps aint exactly hermetically sealed things ...

Either way,. if it happens on a schedule it is the computer doing it ... And if that is the case, then someone wrote that code to serve some (believed to be) logical reason ... I cant for the life of me figure out what that might be though ....

At face value, it does not seem necessary or reasonable .... So either it is just a bad error or there is some reason we are unaware of ... Defrost cycle seems to make some sort of sense ... But then I have to ask, why is this the only vehicle in my life or memory that has needed it ???

As a person who has done automotive ac..... In the past they were no so efficient or they DID freeze up. Yes these are sealed better than many vehicles. I noted in my Chevy manual there were warnings about using or not using the outside air. The owner manuals of the past explained it .. At dr. Office more later.

OK - back from doc and errands.
My SX4 has a combination of the 94 Jeep compressor and otherwise 100% original AC components, all run through the Jeep PCD and PCM I used. If I run it on MAX AC with the lever clear to cold for too long, it starts not cooling so well. But if I set it just off max and let the compressor cycle (that puts the thermostat back in the mix) it will actually cool better longer. Max won't cycle the compressor, the evap eventually freezes up.
My Chevy warned of freeze-up if using - or was it not using? The inside air only setting. Evap freeze-up.
I've owned 4 cars with a "Desert only" setting that didn't cycle the compressor - it was for MAXIMUM cooling - and in Iowa, it would freeze the evaporator over after half an hour.
But running right next to "Desert only" without clicking over to the desert only setting would allow the compressor to cycle and keep the humidity thawed and running off the evaporator. This was normal operation. They were not low, there was nothing wrong. They used to mark it as a warning - if you use this setting it will cool like hell but also freeze the evaporator.

Modern vehicles are much more sophisticated as far as sensing air flow, temperatures in the duct and cabin, even the state of the evaporator.

I'd almost make a bet that this is by design and if it didn't do that, those who crank the AC down to 34 degrees on a very humid day would soon find their AC not working.

OF course I could be wrong - but I've yet to see any explanations other than hate of the system and calling engineers idiots.

Seems like everyone is an engineer and refuses to believe that sometimes there are logical scientific reasons - but if they hate it, then the engineer is stupid or an idiot because "it doesn't work like I WANT it to".

 

[khokhonutt]

Its either a defrost or maybe some means to put "fresh air" into the cabin on some sort of cadence ?

Which would be funny as jeeps aint exactly hermetically sealed things ...

Either way,. if it happens on a schedule it is the computer doing it ... And if that is the case, then someone wrote that code to serve some (believed to be) logical reason ... I cant for the life of me figure out what that might be though ....

At face value, it does not seem necessary or reasonable .... So either it is just a bad error or there is some reason we are unaware of ... Defrost cycle seems to make some sort of sense ... But then I have to ask, why is this the only vehicle in my life or memory that has needed it ???

The HVAC issues I've had in my last two FCR vehicles remind me of a bomb lift trailer I worked on in the 80s. It's clear the engineers came up with some of their ideas while they were drinking or enjoying some other form of mind enhancement. It's also clear those engineers have never actually used the products they designed for any meaningful amount of time. I get the distinct impression they crap in the yard, consider that a good job and leave.

 

[kabookie10]

UPDATE! Weather has warmed up nicely here in Houston. Had roof off, doors on on a cool morning on my way in to work (45 min. commute) and noticed it blows ice cold when set in the 80's. Same issue just reversed. If I click to "HI", it goes to Hot Lava, ..have to mess with it up and down to finally get it to find a "warm". I wonder if FCA will ever recognize there is an issue. I just keep waiting on that TSB. I still love my Jeep, but damn, c'mon man!

I have the same issue!!!!!!! Did you find anything out? At least I’m not alone. I noticed if you turn it to high and come down it will gradually go cold. But the other morning when it was cold here and the cabin was cold I set the temp to 75 and it seemed to work fine. I’m beginning to theorize that the temp sensor in the Jeep is regulating the temp based on the cabin temp. If it’s above the set temp on the hvac it’s going to blow cold to bring the temp down.

 

[93civej1]

Anyone had this fixed yet?
Im not sure if I have the same issue, but i picked up a new 2020 (August build) Sport S this weekend. I now have 200 miles on it. Noticed while driving this weekend, we had the AC going. I am not sure if the wife changed anything, I dont believe she touched it, but at one point it went from great AC feel to all of a sudden it felt like outside humid air was coming in. We only had the dash vents going. I am not sure if she noticed it, but I could feel it all over.

I put my hand up on the vents, it was still cool, but it was like it was mixed with outside air coming in even though RECIRC was still on and had not been touched.

Does anyone experience anything similar to this?

 

[ShadowsPapa]

Welcome to modern HVAC - as has been pointed out, this is normal if it's happening on a regular cycle.
People just aren't used to it. They don't like it. But I'm betting it's not a bug if it's a regular cycle to introduce outside air and/or defrost the evaporator.
There are TSBs out there for bad connections that cause the thing to randomly allow humid air in due to a mix door control or something like that, I didn't read the TSB fully, but when it's a regular cycle with AC on, it's design, not flaw.
people hate what they don't understand or see a reason for - this MAY be one of those things.

 

[93civej1]

Welcome to modern HVAC - as has been pointed out, this is normal if it's happening on a regular cycle.
People just aren't used to it. They don't like it. But I'm betting it's not a bug if it's a regular cycle to introduce outside air and/or defrost the evaporator.
There are TSBs out there for bad connections that cause the thing to randomly allow humid air in due to a mix door control or something like that, I didn't read the TSB fully, but when it's a regular cycle with AC on, it's design, not flaw.
people hate what they don't understand or see a reason for - this MAY be one of those things.

Any idea what the TSB is? I saw the one posted directed toward JL's.

 

[MrZappo]

You would think that with as many people are asking questions about this (all over every forum and youtube) that FCA would simply put the issue to bed by telling us how it actually works ..

I for one think that manual mode is manual for everything except for temperature control ...

People want manual mode to work like their 1974 Chevy nova where they can make the output air whatever temp they want it to be ... Basically they want to control the "mixing valve" directly without the computer thinking for them ... They want to tell the truck to blow cold air until they tell it to stop ...
I believe that the system is trying to regulate the output air temp to reach a desired temp. Normally this is done with a computerized PID loop which can seem random to people although it is adjusting things with some logic ..

That plus the (every 40 minute) hot air dump is very irritating ...

 

[ShadowsPapa]

You would think that with as many people are asking questions about this (all over every forum and youtube) that FCA would simply put the issue to bed by telling us how it actually works ..

I for one think that manual mode is manual for everything except for temperature control ...

People want manual mode to work like their 1974 Chevy nova where they can make the output air whatever temp they want it to be ... Basically they want to control the "mixing valve" directly without the computer thinking for them ... They want to tell the truck to blow cold air until they tell it to stop ...
I believe that the system is trying to regulate the output air temp to reach a desired temp. Normally this is done with a computerized PID loop which can seem random to people although it is adjusting things with some logic ..

That plus the (every 40 minute) hot air dump is very irritating ...

LOL - yeah, I enjoyed that - in a GOOD way. You have points, and that last line - 100% if FCA would only explain in the OWNER MANUAL or deailer training "if you feel warm and/or humid air at regular intervals (for example, every 30 to 40 minutes) this is the system introducting outside air (and/or defrosting the evaporator)
If a TSB applies to Wrangler in the last couple of years - well, where does the JT system come from?
It's not a new invention, not a totally new design from the ground up - like the dash, it was pulled from other Jeeps. So if there's a TSB about 2019 and 2020 Wrangler, you can suspect at the very least, JT could be included. Only the stuff below the cab and behind the cab is new design - or is it? Ram, anyone?

Like I've said before - if I run my SX4 AC on MAX and high fan for long, it stops cooling becuase in Iowa, I freeze up the evaporator because the compressor is locked on and the thermostat looped out of the system. But move it off max just a bit, let the compressor cycle, it will blow cold enough I eventually turn it up a bit warmer.. And some used to have "desert only" settings for good reason - evaporator freeze up. So those with a JT in a humid climate running the AC at 60 degrees will freeze the evaporator. When I did automotive AC work, we could check the air out the vents in the dash and get 34 degree air - so what's the temp of the evaporator? Likely COLDER - as a multi-million dollar U.S. Navy study found a few years back (and I am NOT kidding) one of the results of plain water reaching 32 degrees is that it - freezes. (wonder what that study cost each of us)

So I may be reaching, on the other hand, I've seen hints in the documents that the regular cycle is indeed intentional. So when people say it simply randomly dumps warm air - is it random? Be sure - time it next time on a drive that's 2 hours or longer with AC running STRONG.

 

[Deleted member 20081]

Just took delivery of our 2020 Gladiator last week and absolutely love it!

Has anyone had issues with hot air blowing out at settings of 60 or higher? If we bring it to Low and begin feeling cooler air and then increase to 65 it's fine for a moment. Then, hot air begins to blow and it feels the same if we have it set at 65 or 80.

Dealer looked at it and told us no codes showed up when analyzing and that there have been no issues reported, however this doesn't seem right. They recommended we drive it for a bit and see what happens.

Any thoughts on this would be appreciated. Thanks!

My GT blows good air conditioning and then blows hot. It cycles. Hot cold hot cold. It comes in waves. We are at 6000k miles and discovered the issue driving from Va to Fla and back. Wrote it up on the forum but haven’t had time to take it in yet

Sponsored