A/C Issues? Anyone else

[2019_Ram]

I was driving back from Laughlin through AZ on Sunday with the AC on (cabin recirculating). About ever half hour it seemed like the recirculating door would open to outside air for a minute or so then close to recirculating again. We did drive through pretty high cross winds. Is the system supposed to do that or was it the cross winds causing it?


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Mine does this too and has done so since purchase. I think it is normal operation. Mine is not very subtle at highway speeds and took a while to get used to it.

 

[BroKV]

Mine does this too and has done so since purchase. I think it is normal operation. Mine is not very subtle at highway speeds and took a while to get used to it.

Interesting, mine isn’t subtle either. Kind of sounds like the door is opening and trying to close but struggling.


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[gimmie11s]

I have a 2021 and the AC is terrible. I have a really good Fluke Digital volt ohm meter and I can hook up a thermocouple and I have driven around and done tests in various conditions. I tape the thermocouple probe in the Driver’s side Panel Vent.


My Truck actually will meet their performance test. 54 Deg vent temp with outside air temp of 90. You can set your spec anywhere you want. But that does NOT make it cold or good by any means. I paid for Tech Authority and went in and downloaded all the info on the system in my Truck. I have had it at the Dealer twice and they opened up a STAR case and they have not been able to fix it. Yes, they have NOT been able to fix it. What is broken you say if it meets spec? Well, on an 81 deg day, after just turning off the AC with this 54 deg air coming out, the vent temp will go up to 103. My Truck actually HEATS the ambient air coming in when on the coldest setting, what I would call VENT. So, on a 68 deg Day I am sometimes forced to run the AC because I get so hot. In any other Vehicle I would not likely have to run the AC until I reach 78 to 80 outside air temp. I like it warm but this is ridiculous.

I could not find a detailed coolant flow diagram on Tech Authority. Just a basic one. I wanted to do the Muzzy Hack, but a master Tech told me he does not think that is such a good idea. W E L L , I went under the hood of my Truck and I traced out the system. As far as I can tell the Heater core is supplied from a fitting from the top of the exhaust manifold. The EGR cooler is supplied from a similar fitting off the top of the exhaust manifold. The Turbo cooling is supplied from a Banjo Fitting from the lower front of the cylinder block. All three of these return to a manifold and go down towards the front lower of the motor. I assume the Suction of the Water pump. There is also a vent coming from that manifold to the top of the coolant recovery tank. I assume to bleed out air or create minimum flow. So, I see no reason why the Heater Hose could not be pinched. If anything, it might help flow through the EGR cooler and Turbo. Correct me if I am wrong.

I am going to pinch the Heater Hose with a tool from Harbor Freight. I would MUCH rather be cold and not have HOT air coming into my face when I am on the VENT setting. I want to breath cool fresh air. Hot air makes me sick. I am not going to install a Ball Valve. Pinch is more my style and I am not paranoid about it failing. It won't do any more to that hose than a typical Corbin clamp would. Period.

The rest of this Truck is TOO GOOD to give up on it. But, it's also good that Chevy and Ford do not make a MegaCab. Otherwise, I might have a decision to make.

I agree with what you say. But I know all the folks at my Dealer and my Loaner is free. I have done a lot of testing on my Truck and I have seen some shocking things. For instance there is a "in cab tempature sensor" on BOTH the system description and the wire diagram for 2021 Ram 3500 with MTC. My truck does NOT have one. So, is it just misplaced and sitting on top of the HVAC housing, or was it removed from the system by FCA, and the desc and prints not updated? With Covid everybody is making excused to not do their job.

On a 75 Deg Day on initial startup with a cold engine, with the Heater core in service I can start my Truck and drive. The temp will go down to 42 and then the heater core takes over and the temp will slowly rise to 54. If I pinch the heater hose the temp went down to 26! TWENTY SIX.

I am also going to remove my Cab Air Filter and tape off about 1/2 of the surface area. When my Truck is traveling at 65 MPH and it changes from recirc to outside air the airflow quadtriples. It basically makes fan speed ONE like Fan Speed 4 when I am on Fresh Air and going 65. This forces me to move the air down to the floor because when I am traveling it dries out my eyes and they are constantly burning. I have NEVER had a vehicle do this.

Trust me, I have a 3 page rant I could post. And I HATE BITCHING.

These are GREAT posts.. some of the best in the whole thread with real data. I was going to suggest the "pinch" idea to the guys installing ball valves because they were reporting good results, but you beat me to it. What are you using to pinch the hose?

I completely agree.. .the truck is SOOOOOOOOOOOO amazing everywhere else, it is absolutely worth "figuring out" a fix on our own and making it work. I wont have any dealer monkeys touching an $80k+ truck making things worse as they leave black grease marks all over.

I was driving back from Laughlin through AZ on Sunday with the AC on (cabin recirculating). About ever half hour it seemed like the recirculating door would open to outside air for a minute or so then close to recirculating again. We did drive through pretty high cross winds. Is the system supposed to do that or was it the cross winds causing it?


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Mine does this too.

Then to @DRAGRAM's point, my vent pressure will sometimes be much higher than my recirc pressure--which should NOT be the case.

 

[DRAGRAM]

These are GREAT posts.. some of the best in the whole thread with real data. I was going to suggest the "pinch" idea to the guys installing ball valves because they were reporting good results, but you beat me to it. What are you using to pinch the hose?

I completely agree.. .the truck is SOOOOOOOOOOOO amazing everywhere else, it is absolutely worth "figuring out" a fix on our own and making it work. I wont have any dealer monkeys touching an $80k+ truck making things worse as they leave black grease marks all over.




Mine does this too.

Then to @DRAGRAM's point, my vent pressure will sometimes be much higher than my recirc pressure--which should NOT be the case.

Here you go. I am also going to carry a 5/8 Hose union and a couple clamps in the Truck just in case it starts leaking (I doubt it will).

I've got much more. In fact my Truck has a programming error. My AC goes into recirc mode even when I just enable regular AC. So my truck is programmed to fool me and give me MAX AC regardless if I ask for it or not. I hate this because in every vehicle I have had for the last 40 years I never use recirc. I very much prefer fresh outside air. I get car sick and have since I was a child. I discovered a work around that is 100% repeatable but it is a Pain in the Ass !

Fluid Line Clamp Set, 4 Piece

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[kristof]

After posting this I thought about it a little more and decided I should give a little more information. I'm wanting to compare how my truck acts to another, especially if you have really good cold ac.

When I start my truck anywhere from 65*-85* outside temp (these are the temps I have had so far), Max AC on, the truck will take 1-3 minutes of continuous AC compressor engagement. After that initial cycle, the compressor will start kicking in and out about every 10 seconds, even though Max AC remains on and the cabin warm/hot. Every other vehicle I have owned seldom cycled the compressor when Max AC equivalent was called for, unless it was low on refrigerant. I am concerned this is a symptom of another underlying issue that is preventing the system from performing to it's full potential and I do not believe it is undercharged.

Thanks!

Have anyone installed the valve on 2020 2500 and could show me where to place it exactly?

 

[DRAGRAM]

Have anyone installed the valve on 2020 2500 and could show me where to place it exactly?

It's on the Pass side of the engine. It's actually the return line from the heater core. The supply line to the heater core comes off the top of the exhaust manifold and goes straight back to the firewall way up under the Cowl. You might even need a flashlight to look back up there. Then next to the supply line is the return line. It is covered with silver metal insulation. It connects to a cast metal manifold where the other lines from the EGR cooler and the Turbo attach. There is also a smaller rubber vent line that goes to the TOP of your coolant recovery tank (white plastic tank in the very corner of the engine compartment behind the Pass side Battery, I think). Top Center of this pic is the metal cover on the EGR cooler. Ball valve has a Blue Handle.

 

[kristof]

It's on the Pass side of the engine. It's actually the return line from the heater core. The supply line to the heater core comes off the top of the exhaust manifold and goes straight back to the firewall way up under the Cowl. You might even need a flashlight to look back up there. Then next to the supply line is the return line. It is covered with silver metal insulation. It connects to a cast metal manifold where the other lines from the EGR cooler and the Turbo attach. There is also a smaller rubber vent line that goes to the TOP of your coolant recovery tank (white plastic tank in the very corner of the engine compartment behind the Pass side Battery, I think). Top Center of this pic is the metal cover on the EGR cooler. Ball valve has a Blue Handle.

I see. Thanks for the explanation. Can't wait to install it and feel cold air again

 

[davemc]

Bought a 2021 AC not working took it back to the dealer he said they’ve had a rash of them not charged from the factory this was built in December 2020 but it’s gonna take two days to get the truck back for them to charge it don’t quite understand it. Anyone else having issues?

I'm having the same issue with my 2020, 2500 Ram Diesel. I took it back to where I bought it and they stuck a thermometer in the driver vent and said it was normal at 53 degrees. I have a 2017 Charger that blows much colder air. Even if this is "normal" I don't think it's right. Was yours fixed when you got it back?

 

[Gondul]

Preface, I'm not a mechanic nor have I have slept in a Holiday Inn...
So rather than a manual valve under the hood, which I think would be a pain and I'm not sure if entirely cutting off flow to the heater core is a great idea, how about an Electric Heater Control Valve?
I've found some vacuum operated ones, but not sure where they would hook up.

Chevy Parts » Heater Control Valve - Electronic

Chevy Parts - Heater Control Valve - Electronic - OAP50-1555

www.chevsofthe40s.com

 

[Gondul]

I'm having the same issue with my 2020, 2500 Ram Diesel. I took it back to where I bought it and they stuck a thermometer in the driver vent and said it was normal at 53 degrees. I have a 2017 Charger that blows much colder air. Even if this is "normal" I don't think it's right. Was yours fixed when you got it back?

If the dealer is willing to work with you, they can elevate the issue, but most dealers won't.. it is within 'spec' and they are under no obligation to do anything.
You can go to this thread (https://hdrams.com/forum/index.php?threads/ramcares.2453/) and start a conversation with RamCares...

I had the TSB done on my 2019 and while the AC is 'better' it certainly does not blow as cold as I would like.. and it is only June here in Flori-Duh... waiting to see how Jul/Aug works out.

 

[switz]

I had the TSB done by my dealer as my air wasn't cool. Now, with over 100 degrees of heat, the thing rocks. I can't have it in Max for more than a few minutes before I am freezing and have to turn it to auto. I took the attached picture and the laser was pointed into the opening before the air hits the cab. I took a reading at the opening and it was around 34 degrees. If your dealer hasn't done the TSB, find one that will. Mine did it on my word during the winter.

 

[Gondul]

I had the TSB done by my dealer as my air wasn't cool. Now, with over 100 degrees of heat, the thing rocks. I can't have it in Max for more than a few minutes before I am freezing and have to turn it to auto. I took the attached picture and the laser was pointed into the opening before the air hits the cab. I took a reading at the opening and it was around 34 degrees. If your dealer hasn't done the TSB, find one that will. Mine did it on my word during the winter.

I had the TSB done and it blows cooler... within 5 min or so it is tolerable in the truck (prior to the TSB it still wouldn't be cool after a 30-45min ride home), but while 'better' it is certainly not cold enough for me to turn it down from MAX.

Driving in FLori-Duh... 90+ degrees and 95%+ humidity for reference.

 

[Gondul]

The problem with that is you have to cut both supply and return lines and splice into them. The supply line is entirely under the cowl and there is no room to work. There is also limited room for the Device. I actually bought an electric 3 way ball valve. It's very cool. I tested it on the bench. I went out to the Truck to install it and in 5 minutes I decided it was going to be too much to install it. Not really any room for it and access to the supply line is limited. So I put the Valve on E-Bay at a big discount to what I paid if anyone wants to give it a go..........

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Well, yes, both lines would need to be cut...
I personally haven't looked under the hood, this isn't something I'm going to do until the warranty expires.

I based my thought on the controller entirely on the pictures on this board (yours included) where it appears there is room... if you say there isn't, then there is isn't (shame though as it would seem to be an easy fix this way)

 

[davemc]

I had the TSB done by my dealer as my air wasn't cool. Now, with over 100 degrees of heat, the thing rocks. I can't have it in Max for more than a few minutes before I am freezing and have to turn it to auto. I took the attached picture and the laser was pointed into the opening before the air hits the cab. I took a reading at the opening and it was around 34 degrees. If your dealer hasn't done the TSB, find one that will. Mine did it on my word during the winter.View attachment 18064

Do you know exactly what they did to fix the problem and how long did it take?

 

[Gondul]

The Valve you posted would work way better if the inlet and outlet arrangement kept both lines in Paralell as it appears it does. And, there may be physically enough room in there but good luck doing it. If you are going to wait for the warranty to expire that will be a while.......

With my valve you would have to put a T in the supply line and route new hoses etc. It would be a nightmare.

You would need to be sure to get all the air out of the system or damage to the EGR cooler could result.

.

Ok, I realized we have a disconnect...
I have a gasser so 5yr 60k and I'm pretty sure I don't have an EGR.

It appears I may have enough room to put in that valve, provided those two hoses goinf into the firewall are the heater core hoses.
I would just need to figure out how to run the the wires for controller inside to adjust how much coolant goes into the core

 

[switz]

Do you know exactly what they did to fix the problem and how long did it take?

They did the TSB from Ram. It took a day and a half. They had to pull the dash out and according to my dealer, he had only one guy he trusted to do the job. They did a great job and I was afraid of noises coming from the dash after they pulled it. Absolutely no issues and rock-solid air conditioning.

 

[RAM_Dad]

Is this the TSB people are having done?

 

[Gondul]

Do you know exactly what they did to fix the problem and how long did it take?

What is done is listed here https://hdrams.com/forum/index.php?threads/ac-fix-tsb-pre-8-20-build-trucks.3162/

It took them about 4 days to do mine... it actually had to go back as the new unit also had a bad blend door.
They did a great job of putting it all back together... no marks that I can see and no noise.

 

[Gondul]

Is this the TSB people are having done?

Yes, that is TSB

 

[RAM_Dad]

I haven't read through this whole thread, but is anyone with a 2021 having crappy AC performance. Just curious if it seems to be resolved on the builds after the TSB was released.