2019 Ram Air Conditioner (automatically comes on)

[BoBosarge]

So I have a concern about my Ram's air conditioner. During the February/March time frame when outside temps were averaging in the low 60's, there was no need for the air conditioner so it was turned off. BUT with the fan blowing just to keep fresh air in the truck, the air conditioner would AUTOMATICALLY come on and freeze us out. I would have to turn the digital temp dial up to 80 to warm the freezing air that was coming out of the vents. The a/c compressor would run for 3 or 4 minutes and then would turn off which in turn would cause me to turn the digital dial back down to 70 so that we didn't start sweating. During a 30 mile drive to work the a/c (even though it is turned off) will come on and shut off 4 to 5 times causing me to constantly adjust the temp dial to keep the cabin at a comfortable temp. Obviously since we are now in the summer months the a/c is on constantly but there have been a couple of mornings where the temps were in the low 70's and I turned the a/c off but still it would automatically come on while driving down the interstate. The dealer refused to look at it because he said that it automatically operates to hold the cabin at a constant temp even though the button to turn the a/c on is selected OFF. This made no sense to me because if this theory is correct then technically I should not have to ever turn the a/c on but rather just keep the digital setting at 70 and it should maintain that temp. It's in the mid 90's where I live and I can promise you it will not cool the cabin down unless you turn the a/c on! Has anyone else had this issue of the a/c coming on by itself? It can be very frustrating when you don't need the a/c!!!

 

[duke2001]

So I have a concern about my Ram's air conditioner. During the February/March time frame when outside temps were averaging in the low 60's, there was no need for the air conditioner so it was turned off. BUT with the fan blowing just to keep fresh air in the truck, the air conditioner would AUTOMATICALLY come on and freeze us out. I would have to turn the digital temp dial up to 80 to warm the freezing air that was coming out of the vents. The a/c compressor would run for 3 or 4 minutes and then would turn off which in turn would cause me to turn the digital dial back down to 70 so that we didn't start sweating. During a 30 mile drive to work the a/c (even though it is turned off) will come on and shut off 4 to 5 times causing me to constantly adjust the temp dial to keep the cabin at a comfortable temp. Obviously since we are now in the summer months the a/c is on constantly but there have been a couple of mornings where the temps were in the low 70's and I turned the a/c off but still it would automatically come on while driving down the interstate. The dealer refused to look at it because he said that it automatically operates to hold the cabin at a constant temp even though the button to turn the a/c on is selected OFF. This made no sense to me because if this theory is correct then technically I should not have to ever turn the a/c on but rather just keep the digital setting at 70 and it should maintain that temp. It's in the mid 90's where I live and I can promise you it will not cool the cabin down unless you turn the a/c on! Has anyone else had this issue of the a/c coming on by itself? It can be very frustrating when you don't need the a/c!!!

Are you saying there is no way to turn everything off completely if you so desire? That doesn’t seem right ? Sorry to ask but are you following the manual operating instructions and not just trying to operate it intuitively?

 

[BoBosarge]

Are you saying there is no way to turn everything off completely if you so desire? That doesn’t seem right ? Sorry to ask but are you following the manual operating instructions and not just trying to operate it intuitively?

Yes I am following the directions and operating it correctly. What I am saying is when the green light is off (on the temp control knob), meaning the a/c is off, and the fan is blowing (just to circulate air in the cabin), the a/c compressor will still come on intermittently and freeze you out of the truck. Even when it is 50F outside and the fan only is running with the temp dial set at 70F (so that you are adding a little warmth to the cabin), the a/c will be turned off and still the a/c compressor will start which in turn drastically decreases the temp of the air blowing out the vents.

 

[stevenpiper]

Hello there! It's a strange problem to be sincere as I understand your aircon not cooling when you want, and sometimes it works uncontrollably. Several things can cause electrical issues for your car's air conditioning. These can include failed switches, a blown fuse, a problem with the control module, or something else. Fuses can short out and make the A/C stop working, or a loose connection can create an electrical short that is easily fixed. Go to a car service and they should fix the problem! I hope my post helped you. Good luck and have a nice day!

 

[Maksym Ukraine]

Good afternoon. I have the same problem. The air conditioning compressor drive turns on by itself whenever it wants, regardless of whether the button is on or not. Periodically, the electric clutch engages spontaneously. I'm in another country and there is no dealership that repairs it here. Have you solved this problem?

 

[jamiehughes]

ya know that when you got the heat or defroster on that they ac clutch will cycle also? it's how it's supposed to work..

 

[kapinallinen2]

The air conditioning compressor drive turns on by itself whenever it wants, regardless of whether the button is on or not. Periodically, the electric clutch engages spontaneously.

It is "automatically lowering the humidity in the cabin for greater passenger comfort" and also making defrost more effective.

 

[Maksym Ukraine]

So, even if I turn on the airflow direction only for my feet, the compressor still turns on periodically? For drying?

 

[kapinallinen2]

So, even if I turn on the airflow direction only for my feet, the compressor still turns on periodically? For drying?

That is my understanding of how the system works.

 

[Maksym Ukraine]

My air conditioning compressor periodically turns on and blows air onto my feet. Is this how it should be?

 

[Maksym Ukraine]

I mean, when the interior heating is on and the direction is only for the legs, or for the face and legs, it still turns on periodically.

 

[kapinallinen2]

I mean, when the interior heating is on and the direction is only for the legs, or for the face and legs, it still turns on periodically.

A snippet from the owners manual.
"For Manual Climate Controls, if the system is in Mix, Floor
or Defrost Mode, the A/C can be turned off, but the A/C
system shall remain active to prevent fogging of the
windows"
This should also apply to automatic climate control that my truck has.

 

[RHO]

In my wifes edge in the winter in auto you set it to 70 -75 when the car is warming up the unit does not run until the engine starts warming up I have noticed in my ram big horn you have the temp set for 70-75 during the winter and you are just blowing cold air around till the engine gets warm , I wonder if that is what he means ?

 

[Maksym Ukraine]

No, I mean the clutch that drives the air conditioning compressor. This clutch sometimes engages the compressor, but the engine cooling fan doesn't turn on. This could be related to the dehumidification function. I thought the dehumidification function only worked when the windshield or footwell airflow mode was turned on. But it works in all modes. I don't think that's normal. Another thing: when the air conditioning is running, the engine cooling fan also turns on. This is standard. But when my compressor engages on its own, the fan doesn't turn.

 

[kapinallinen2]

No, I mean the clutch that drives the air conditioning compressor. This clutch sometimes engages the compressor, but the engine cooling fan doesn't turn on. This could be related to the dehumidification function. I thought the dehumidification function only worked when the windshield or footwell airflow mode was turned on. But it works in all modes. I don't think that's normal. Another thing: when the air conditioning is running, the engine cooling fan also turns on. This is standard. But when my compressor engages on its own, the fan doesn't turn.

The engine cooling fan turns on when necessary, ie. when parked or driving and the high side pressure reaches a set point requiring more air flow across the condenser or when the AC is set to max.
IMO your HVAC system is fine, unless it is not keeping the interior cool or warm and with in tolerable humidity and comfort level.