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A/C Performance

scottmoyer

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I need to ask a few questions and see if I'm experiencing similar with my 2021 Rebel.

Yesterday was a mere 50* in Orlando. My truck was sitting in the sun, so it was warm inside. I just had the windows tinted so I couldn't put the windows down and I set the AC at 70*. Granted, that was 20* warmer than outside, but I had massive heat blowing through the vents. When it's hot outside, 70* settings blows cold air, so I expected that I would get cooler air than what was already in the truck. After a few minutes of heat blowing, I turned off the AC and was hoping to get 70* air through the vents from outside air, but again, it was hot air.

Is there an algorithm that compares the outside air to the inside setting and blows accordingly, regardless of actual inside temp? I had a similar problem in my '15 Charger where the AC was set on 70*, but the outside sensor got a short and defaulted to -82*. It was blowing on high heat trying to get to 70* from -82*. There's no reason that I should have had that much heat in the truck yesterday when it was probably already over 70* inside. How do you get just vented air from the outside? Just turn off the AC and turn the temp to the lowest setting?
 

Trippi

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I'm wondering if I have this issue. It is cold here in NY 32 degrees yesterday. The sun was out and I was a bit overdressed so was HOT driving. I actually switched the AC on LO and really didn't think it got all that cold in the truck. Would it not get that cold given the outside temps? What would be the best way to determine how well my AC is working? Should I wait until summer? Thanks in advance.
 

KcRay

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I'm wondering if I have this issue. It is cold here in NY 32 degrees yesterday. The sun was out and I was a bit overdressed so was HOT driving. I actually switched the AC on LO and really didn't think it got all that cold in the truck. Would it not get that cold given the outside temps? What would be the best way to determine how well my AC is working? Should I wait until summer? Thanks in advance.
Test now and in the summer, with a thermometer. Check the vent to the left of your info screen, and the vent to right of screen. Coldest setting, recirculation on.
 

STI_MECE

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Just chiming in here....in my experience if the outside temperature is lower than what you have it set in the cabin, then yes technically it's warm air. The condenser is similar to the radiator and the liquid inside the condenser exchange with the outside air. But simply put cold air will typically be dryer than hot air. The AC system will perform before relative to the outside air if the air is humid and hotter than what is inside.

On a hot day where it's hotter than what the AC is set on the inside:

The liquid inside the condenser will absorb that heat (positive Delta) and then the moisture is squeezed out and your left with cold air.

On a cold day where it's hotter on the inside than outside

The liquid going through the condenser is getting cooled (negative Delta) so there is actually less moisture in that gas to be squeezed out this leading to a warmer feeling.

It's the laws of thermodynamics at work.

Sent from my Pixel 3 XL using Tapatalk
 

ZombieSlayer

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Finally was able to keep an appointment at the dealer for a variety of issues. This is the one that is pertinent to this thread.

Customer states that the AC is not blowing as cold as it was when purchased.

Hi and Lo shreader leaking, seal at suction line leaking, humidity upon inspection confirmed customer concern. Found that AC temp was aprox 7 deg F higher than it should be for the current humidity and temp. Checked temp and pressures, found pressures to be low. Using leak detector and UV light found 3 leaks. PA parts for repair.

So apparently my AC system was leaking. Just waiting on parts. The tech said the leaks were real hard to find and using the UV light was the key to finding them.

The parts finally arrived and have been installed.

Leaking low and high side shreader valves. Damaged suction line upon inspection confirmed customer concern, found that the high and low side valves are leaking. Also noted that a suction line O ring is leaking. PA parts. Replaced high side valve, removed low side valve and noted large amounts of metal in threads. Attempted to install new valve noted that valve did not thread in properly. PA suction line from pump to junction that contains the valve. Replaced line. Filled system and tested. System operating as designed. Charge system 0.510.

Parts:

68100680AA seal slim line
68237083AA valve a/c line
68237075AA valve a/c line
68277012AB line a/c suction

I personally haven't tested the a/c system yet, it's 44 degrees outside and I only had time to drive it from the dealer to work which is about 2 miles. I'll test the system next week on my days off and report back.
 

Rototerrier

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Kinda funny now that this is happening. For years we had folks telling us that theirs works just fine and that nothing could possibly be wrong. Just goes to show these forums are full of nut jobs. Never could understand why someone would assume that because theirs works fine that everyone else was insane for questioning their A/C systems. So glad to see something is finally getting done. I now have 25600 miles with plenty up time left on my warranty. Going to wait until warmer weather before taking mine in. Unfortunately, I'm in the Metro Atlanta area and the only dealerships we have are gheto as hell and do horrible work. I'll probably have to take mine to a dealer some distance away to try to get some decent service. I'll probably never buy another ram for as long as I continue to live in this area just because of the lack of good dealer support. My area is saturated with ford and gm.
 

Ellisstrong

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Kinda funny now that this is happening. For years we had folks telling us that theirs works just fine and that nothing could possibly be wrong. Just goes to show these forums are full of nut jobs. Never could understand why someone would assume that because theirs works fine that everyone else was insane for questioning their A/C systems. So glad to see something is finally getting done. I now have 25600 miles with plenty up time left on my warranty. Going to wait until warmer weather before taking mine in. Unfortunately, I'm in the Metro Atlanta area and the only dealerships we have are gheto as hell and do horrible work. I'll probably have to take mine to a dealer some distance away to try to get some decent service. I'll probably never buy another ram for as long as I continue to live in this area just because of the lack of good dealer support. My area is saturated with ford and gm.
I finally got what I think was good service at Ed voyles in Marietta. Had terrible service at two locations previously in the area. I also have heard good things about the Gwinnett CDJR from my brother in law but that’s too far from me.
 

Rototerrier

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That would be a haul for me to drop off. Since they don't usually offer loaners, it makes it very difficult to get this kind of work done.
 

HemiDude

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So my truck has undergone the TSB repair. I don't know if it made a difference as it isn't all that warm currently, even in Houston!!!! Anyway the car seems to be put back together without issue, and I am very aware of minor changes/noises, etc., from my years working in an automotive assembly plant. I am attaching my service report for those interested. View attachment 77193
I thought I read in the TSB that an evaporator was included, but it doesn't look like they did one in yours?
 

brian42

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Anyone know where I can find this specific TSB?
Yes, 100 posts prior to yours in this thread.

The full TSB (24-001-20) was posted by NorthStar in post #794 (page 40):

 

ZombieSlayer

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It's still too cold to test the a/c (hasn't been higher then 36F) so guess I'll have to wait a bit. Good news is, the dealership will have the parts for the TSB waiting for me if I need them :)
 

Streetsweeper

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FYI this issue is due to the internal diameter (ID) of the heater hoses. I think read here someone said FCA used 5/8" ? - In any case, this temperature outlet issue only exists because of the hose diameter. You may be able to swap the hoses or use a couple of barbed step-downs to reduce hose inner diameter and see the same results as a valve. Not sure what the impacts/risks are for a valve vs. correct hose ID.
 

Streetsweeper

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FYI Ford's have the highest cooling capacity so look at F150s.
GM likes to source the absolute cheapest supplier so I can't make any comment as I steer clear. Could be fine.
 

Jimmy07

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FYI this issue is due to the internal diameter (ID) of the heater hoses. I think read here someone said FCA used 5/8" ? - In any case, this temperature outlet issue only exists because of the hose diameter. You may be able to swap the hoses or use a couple of barbed step-downs to reduce hose inner diameter and see the same results as a valve. Not sure what the impacts/risks are for a valve vs. correct hose ID.
No, the A/C issue has nothing to do with the heater hoses diameter. It is a combination of the blend doors not sealing correctly (hence the reason for the new HVAC box part number), a duct temp sensor location (the reason for the new distribution box part number and new temp sensor), and HVAC module mapping (the reason for the new HVAC module part number).
 

Checkairspeed

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No, the A/C issue has nothing to do with the heater hoses diameter. It is a combination of the blend doors not sealing correctly (hence the reason for the new HVAC box part number), a duct temp sensor location (the reason for the new distribution box part number and new temp sensor), and HVAC module mapping (the reason for the new HVAC module part number).
Dang. Thought Streetsweeper had all the answers.
 

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