FCA Cross-platform HVAC Issues

[Catless]

"If I set the temp to 68, the air blows out at 68, whether it's AC or heat."

This is a misunderstanding of an automatic temperature control system as in the newer vehicles. You are not setting the temperature of the air the system is putting out, you are setting the temperature you want the cabin. Just as in a home HVAC system when you set a temperature you are setting the house inside temperature you want to maintain, not the temperature of the air the system produces.

I despise all automatic temperature control in vehicles because they do not work under most conditions with the exception of a long trip where the system has enough time to stabilize. I would prefer a manual control system where you do set the temperature of the air the system is producing. Unfortunately most vehicles today are not even available with a manual system.

 

[04Ram2500Hemi]

I've noticed my Challenger can be a challenge to get the right temp. If I set the temp at 72f it blows way warmer than that. In order to get my A/C to work I have to set the temp around 66f and set the fan speed on high, and then after a few minutes I can set the temp to 72f and have it actually blow the correct temp. There's something to be said about the simple rotary dial on the dash of my Power Wagon.

 

[SpecOps Veteran]

Sometimes mine blows hot when I don’t want it to. I believe it’s sensing that the outside temperature is cold and wants to give me heat. I just put it on auto air and close my vents. Sometimes it is blowing a mix of (cool) air to regulate the temperature when I really want heat. I usually can get hot air to come on by jacking the temperature up. Mostly, I think it is working the way it was designed by computer and sensors but I often miss the old manual temperature and fan controls.

This is exactly my point. I traded a 2017 Ford Fusion in on my Scatpack, then my Charger. If its 40 degrees outside, and I set the temp to 68 in the fusion, it would mix the air with heated air and make it come out at 68 degrees, not try to make the whole interior 68 degrees. If it was 75 outside, and I set it to 60, it wouldnt blow below 75 plus the minimum amount of heated air that would get blown in. But the Charger just blows random weird shit and it pisses me off. I don't care if my interior is at 40 degrees, I want the temp to blow at 68 because it's blowing on me and that's what I need to be comfortable.

 

[SpecOps Veteran]

"If I set the temp to 68, the air blows out at 68, whether it's AC or heat."

This is a misunderstanding of an automatic temperature control system as in the newer vehicles. You are not setting the temperature of the air the system is putting out, you are setting the temperature you want the cabin. Just as in a home HVAC system when you set a temperature you are setting the house inside temperature you want to maintain, not the temperature of the air the system produces.

I despise all automatic temperature control in vehicles because they do not work under most conditions with the exception of a long trip where the system has enough time to stabilize. I would prefer a manual control system where you do set the temperature of the air the system is producing. Unfortunately most vehicles today are not even available with a manual system.

Unless you're in a Toyota Camry, or Ford Fusion, or whatever. But the problem I had with the Scat was it would go overboard. Who in here seriously wants 184° air blowing on them? I have over 25 videos of this happening, it wasn't even close to a 1 time thing. And then the area with the sensor would get hot and blow freezing air even tho it's 19° outside and takes 2 minutes for the car to get cold again. My hellcat isn't quite to that level but it flip flops and drives me crazy.

 

[SpecOps Veteran]

This is exactly my point. I traded a 2017 Ford Fusion in on my Scatpack, then my Charger. If its 40 degrees outside, and I set the temp to 68 in the fusion, it would mix the air with heated air and make it come out at 68 degrees, not try to make the whole interior 68 degrees. If it was 75 outside, and I set it to 60, it wouldnt blow below 75 plus the minimum amount of heated air that would get blown in. But the Charger just blows random weird shit and it pisses me off. I don't care if my interior is at 40 degrees, I want the temp to blow at 68 because it's blowing on me and that's what I need to be comfortable.

None of my 15 other cars I have had in the last 10 years EXCEPT FCA products have done this. I can go out in the parking lot and get in probably any car out there and set the temp to 68 and thats what it blows.

 

[Speedy!]

My Camaro dies this to. I don't use the auto temp in any of my cars as they never seem right.

 

[SpecOps Veteran]

My Camaro dies this to. I don't use the auto temp in any of my cars as they never seem right.

I should reiterate it does this without auto-temp engaged. Honestly it does it with or without, either. way.

 

[Diboblo]

I should reiterate it does this without auto-temp engaged. Honestly it does it with or without, either. way.

Did you replace the humidity sensor, yet?

Also, have you scanned the car for code P1009?

All the theories and keyboard troubleshooting mean nothing, until you run a scan

Hope this helps.

Bob
Riverside, California

 

[Speedy!]

I should reiterate it does this without auto-temp engaged. Honestly it does it with or without, either. way.

I missed that and that would be strange. Mine all work as expected out of "auto" mode.

 

[SilverBillet]

Did you replace the humidity sensor, yet?

Also, have you scanned the car for code P1009?

All the theories and keyboard troubleshooting mean nothing, until you run a scan

Hope this helps.

Bob
Riverside, California

I don’t think the issue is affected by the humidity sensor...I agree with the OP, the temp is just hard to regulate. When it blows hot, it is continuous hot until it’s cold. And then it blows cold when you really just want it blowing warm air.

 

[Diboblo]

I don’t think the issue is affected by the humidity sensor...I agree with the OP, the temp is just hard to regulate. When it blows hot, it is continuous hot until it’s cold. And then it blows cold when you really just want it blowing warm air.

Just throwing it out there.

I had the same issue, with P1009, and the sensor fixed it.

It is a code that does not set a light, so you won't know its there, until you look for it.

A scan is free piece of mind

Bob
Riverside, California

 

[SpecOps Veteran]

Did you replace the humidity sensor, yet?

Also, have you scanned the car for code P1009?

All the theories and keyboard troubleshooting mean nothing, until you run a scan

Hope this helps.

Bob
Riverside, California

I have not. I just got my car back on Monday as I was heading out of town and then my wife has surgery this coming week so I will get it into them soon as I can. I will be sure to let you know tho!!

 

[Hickster]

Mr. Gatzby,
I am impressed that you hold a GC license but does that have anything to do with a commercial HVAC license. Gives you the rights to use a contractors HVAC license, but you are not to build your system and or install of course with out a stamped mechanical engineering credentials. Hats off to being able to reinvent the A/C industry in Fl. Very difficult to do. My explanation of a RH and dew points are very different. That was my major as respected as a street engineer to be able to remodel an HVAC system to properly control the balance of the air, cooling coils, insulation, mold, mildew, control system. Most cases Variable speed controls on pumping water systems and sizing equipment to do so. On all my autos I always use the manual controls. The control systems in these sophisticated autos are not the best. Yes, when the glass needs drying out, hit the defrost and heat. Dries out quickly,, with my manual controls. A lot of wiper use works well. Roll down the winders and see what happens,, dew point goes thru the roof with 70% RH and dew point at 80. Basically raining. Turn the heat on and dry out the air. I don't ha ve a GC license but a commercial HVAC, insulation, IAQ, and controls. I do have a state licensed electrian and an engineering company that work under me. Going on 37 years in the business should give me some lea way. Thanks for the cross conversation. Still ductless a/c components are crap. May as have a window shaker. By the way,,, I do not have to paste specifications out of a man u well to speak of this subject. That was a spank. I mostly deal in chill water, glycol, and generation systems.

 

[DGatzby]

Hickster, thanks. Your right, I would not think of doing a thing without you and other great contractors to help us build something. Also, I am not smart enough to design a thing myself. Hats off to you folks keeping everyone warm AND dry at the same time down there. Ha, we have the opposite end here. You will like this...woke up to -14 F and of course my system here at home is struggling to get it at 70 F this morning after the overnight set-back.
Going to do a "day-trip" to a project site today. We built a darn hydro retrofit on a dam. The thing we need to look at today is at the south end of a very long reservoir and not looking forward to that wind slapping at us in these temps! I'll be thinking about my HVAC friends!

 

[stonewall]

I have "Heat Pumps" A big damn joke when temps fall to 32* They do a nice job at 50* LOL In the summer the AC side works very well to keep out the Arkansas 87% humidity. The systems In my Cat has it beat .

 

[Hickster]

Heat pumps are worthless below 40 degrees. I have done a lot of work with companies up north and south with Geo Thermo systems. Great works for heat and very inexpensive. Mr Gatzby, thank you for the nice complement and hats off to ya for sticking in to the construction industry. I can do you any help and the same back,, let me know. Not to pat myself on the back,,, wait I will. I sold, installed and maintained the 1st 5 McQuay chillers on the east coast. A remarkable machine that makes no noise, runs at 35,000 RPMs and with a compressor that uses no refrig oil, can down load to 10% of total load. Runs off of magnets with a levitating compressor shaft that creates no friction. No oil and no moving parts. Variable speed drive on the chiller and pumps makes for a very quiet equipment room. Great for office building whom can not rent space above or below equipment room. Energy efficiency best in the industry. Sorry,, boring for most people. Lived up north at - 14 and heat pumps,, look into geo thermos heat and cooling. Thanks again for the industry kind words.