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Air conditioning Hack

I seriously doubt FCA is afraid of a class-action lawsuit over air vent temperatures of say 52 instead of 42. There's no guarantee on how effectively air conditioning works - so long as it it is removing humidity and reducing the cabin temperature relative to that of outside, it is perfectly operational. "Cold" when it comes to AC is largely subjective.
Well I don't think the customers want to have it come to that, but it might. Be better if FCA stepped up and made some changes that would require a TSB for some vehicles and some minor modifications that are factory authorized.

I think in the mobile AC engineering field, cold is not really subjective in the technical sense, throughout the decades most
engineers seem to consider between 38-42 optimal temperature coming out of the driver's side center vent with
the following. AC on max, recirculate on, fan on high, and car parked outside in ambient temp of 90 F under a shaded area. That is pretty standard and has been I would guess for at least 40-50 years now, at least in the USA and Canada.
 
Well today was a disaster, I could not take the 54 deg temps coming out my truck at 92 deg outside, makes me not even want to drive the damn thing. I tried to do the AC hack and install the valve in my heater core line. Didn’t wait til pressure had gone down and when I pulled the hose off the water pump port it just started spraying coolant everywhere. Lost so much coolant that I couldn’t even drive to get more. Had to wait til the wife got home from work to take her car and buy 2 gallons of OAT coolant. Glad I bought two because in the process of bleeding the coolant system I lost like another half gallon when it geisered not once but twice. Never in my life has that happened to me bleeding a cooling system. Usually you just let it idle til the t-stat opens, watch the bubbles (Air) and then add some more to top it off. This thing was a nightmare, I don’t even know if it’s bleed off properly now.

To make matters worse I got in my wife’s suv to go get coolant and was like god the AC feels so good in her vehicle. A guy should not have to deal with this on a brand new truck and have no help or guidance on how to correct it!
 
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While trying to play with various settings to see if anything helps, it seems that the ONLY way to enable Max A/C is to manually set it through the Climate page, and then, it will only stay in Max A/C if the fan is set to the highest setting (7). If you lower the fan speed, it automatically takes you out of Max A/C. However, raising the fan speed back to 7 doesn't automatically engage Max A/C. You then have to go back to the climate page and select it. And another thing is that when set to AUTO, it doesn't seem to ever put it in Max A/C. I go to the climate page and it's off. I'm sure that's how it's supposed to work, but I don't really like it. I would prefer to have it stay in Max A/C until I decide to take it out of it.
 
I’m in Central Texas. It’s getting hot for sure. About 97 today. I have my hose clamped shut and it’s blowing about 44 - 45 degrees out of the driver’s side center vent. Prior to clamping, it would only blow 52 - 53 degrees. I don’t use the Max or auto setting. I have the temp lowered to the minimum setting and keep it on recirculate. I moderate it with plus/minus fan speed control. Works great for me.
 
Well today was a disaster, I could not take the 54 deg temps coming out my truck at 92 deg outside, makes me not even want to drive the damn thing. I tried to do the AC hack and install the valve in my heater core line. Didn’t wait til pressure had gone down and when I pulled the hose off the water pump port it just started spraying coolant everywhere. Lost so much coolant that I couldn’t even drive to get more. Had to wait til the wife got home from work to take her car and buy 2 gallons of OAT coolant. Glad I bought two because in the process of bleeding the coolant system I lost like another half gallon when it geisered not once but twice. Never in my life has that happened to me bleeding a cooling system. Usually you just let it idle til the t-stat opens, watch the bubbles (Air) and then add some more to top it off. This thing was a nightmare, I don’t even know if it’s bleed off properly now.

To make matters worse I got in my wife’s suv to go get coolant and was like god the AC feels so good in her vehicle. A guy should not have to deal with this on a brand new truck and have no help or guidance on how to correct it!
Oh man we've all had our disasters over the years but take solace in the fact you'll be enjoying cool temps now and forget all about it soon enough.

I hit golf balls the other day when it was 90F and really muggy (don't ask why, lol) and the truck was baking in full sun. Less than 10 minutes after I got in it felt amazing in there. One of those ahhhhh moments.

If anyone who doesn't own a new RAM stumbles into this thread they're going to think we're friggin crazy talking about our cold AC and getting so excited about it.


Sent from my SM-G950U using Tapatalk
 
If anyone who doesn't own a new RAM stumbles into this thread they're going to think we're friggin crazy talking about our cold AC and getting so excited about it.


Sent from my SM-G950U using Tapatalk

It’s so sad that we’re talking about Rams most innovative new $50-$60K trucks and we’re celebrating that we rigged up some spare plumbing parts to get ac temps that every other vehicle regardless of age gets , out of our new trucks!
 
I can’t wait to try clamping off this hose. South Fl has been high 90s and even low 100s. Just bought a brand new limited last month...for the price of that vehicle, I can’t believe I have a sub par a/c! I traded in an F150 that blew way colder...if I can’t get this AC issue fixed I will trade this thing in.
 
Today I was able to get 36-38 degrees blowing out of both the drivers side and the passenger side ac vents. Previously I was getting 44 out of the passenger side and 50-52 out of the driver side. I installed a water shut off valve in the heater hose going from water pump to the heater core. It's the outbound side of the pump says "out"right on the hose. This stops any hot water from getting into the air conditioning system at all. You will have no heat for the heater you will have no way to control the air conditioning temperature it will be as cold as it can be. This was only a test for me if you decide to do this it will be at your own risk. In essence this proves there's definitely a blend door issue inside the dash letting hot water into the HVAC system when we are telling it not toView attachment 25616View attachment 25617View attachment 25618View attachment 25619View attachment 25616View attachment 25616View attachment 25617View attachment 25618View attachment 25619View attachment 25616View attachment 25619
I am going to do this. The AC is complete crap at low speeds for 20-30 min. I am not familiar with vehicle HVACs though. When I start removing hoses what is going to come out of them?
 
I am going to do this. The AC is complete crap at low speeds for 20-30 min. I am not familiar with vehicle HVACs though. When I start removing hoses what is going to come out of them?
Coolant.
 
I am going to do this. The AC is complete crap at low speeds for 20-30 min. I am not familiar with vehicle HVACs though. When I start removing hoses what is going to come out of them?
If you're not macanicly familiar with this process, pay a independent mechanic or ask a friend or neighbor for help. I would think they should not charge more than 1/2 hour labor.
 
If you're not macanicly familiar with this process, pay a independent mechanic or ask a friend or neighbor for help. I would think they should not charge more than 1/2 hour labor.
I know enough to do it I just wanted to make sure I knew what was in the hose. The AC works fine for people who have med to long drives. Not for me who has to drive a thousand different places 30 min or less from each other. Not acceptable.
 
I know enough to do it I just wanted to make sure I knew what was in the hose.

Make sure you do it when the engine is cold! Take a rag and wrap it around the hose coming from the heater core then use a pair of vice grips or a clamp , that way you don’t lose as much coolant. Prepare the valve with the short piece of 5/8 hose and close the valve. As soon as you pull the hose off the water pump port shove the little hose on it as fast as possible since the valve is closed you won’t lose hardly any coolant
 
Make sure you do it when the engine is cold! Take a rag and wrap it around the hose coming from the heater core then use a pair of vice grips or a clamp , that way you don’t lose as much coolant. Prepare the valve with the short piece of 5/8 hose and close the valve. As soon as you pull the hose off the water pump port shove the little hose on it as fast as possible since the valve is closed you won’t lose hardly any coolant
So the confirm, the coolant will come out of the pump, not the hose you are taking off it, correct?
 
It comes out of both, at least by pinching off one side it makes it easier to control how much spillage you have.
 
You would think that FCA would just admit the design flaw/operational failure and fix it. If a guy can come up with $15 fix FCA and all their engineering brain power should be able to remedy this issue.
We are talking about the same people with that engineering brain that designed the adjustable pedal assembly with a brake rod that is too short, hench recall V07. I've got the same problem with my 2019 1500, going to dealership Thursday to drop off, 2 recalls and tailgate and ac.
 
I am going to do this. The AC is complete crap at low speeds for 20-30 min. I am not familiar with vehicle HVACs though. When I start removing hoses what is going to come out of them?
To be clear...There are two systems, one for heat and one for cooling that meet inside the truck. When you limit the hot water flow you allow the AC to be used at a colder temp.
 
To be clear...There are two systems, one for heat and one for cooling that meet inside the truck. When you limit the hot water flow you allow the AC to be used at a colder temp.
That's right, think of the two systems as two separate loops. Simplified, each loop has a pump and a radiator looking component in the dash. Then, again simplified there is one blower fan in your dash that has a door in front of it that can direct the airflow over the hot and/or cold radiators (it can shut off airflow over the hot radiator for full cold or close airflow over the cold radiator for full hot, or anywhere in between for blended temperature air) EDIT: See Tom's more accurate description on the blend engineering below.
The hack shuts off hot water from getting into that hot radiator in the dash, so even if the system has a flaw such as on full cold that blend door is still letting air over the hot side, well the hot side is now not hot so the vent temperatures are that much lower.
 
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(it can shut off airflow over the hot radiator for full cold or close airflow over the cold radiator for full hot, or anywhere in between for blended temperature air).
Not exactly. The air ALWAYS goes over the "cold" radiator, that is only cold when the A/C is running... otherwise it's at ambient temp. and does nothing. THEN the blend door can divert none, some, or all of the air over the "hot" radiator, which is always hot (or, always at engine coolant temperature).

This is how defrost works in the wintertime. First, the incoming air is cooled (and as a by-product, dehumidified). Then it's warmed up again, resulting in warm, dry air blowing out the windshield duct.
 

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