Air conditioning performance

[technicholas]

Ok guys this is what I notice on SUPER humid days the AC sucks. On non humid hot days it seems to cool OK. Not super cold but it cools. It is super bad when it’s humid and over 100 out.

 

[ac1dd]

I am sorry you have had issues, I just thought you would want to know that there was a bios update a complete evac/recharge done and it was also indicated that they charge levels are labeled incorrectly. He indicated halfway and also indicated TSB was issued late last night...... The TSB is 24-001-19 and star case S1924000015. Who knows if the dealer was telling me a correct release date or they just didn’t look at my car day 1 and needed an excuse but I’ll take the cold air. I hope this helps so you can love your trucks again. I know this had me on the edge of a other wise wonderful truck.

Can you measure your vent temps? For reference turn the truck on and run for 15 minutes , A/C on recirculate, fan on middle settings, truck running at idle, and post ambient temps, and humidity. Thanks friend.

 

[ac1dd]

And in the process, that fried his ac compressor from an apparent refrigerant overcharge, and he was told the compressor part was then on back order. Folks are just trying to nail down the entire situation.

The two specs are within 2 ounces of each other. It is UNLIKELY that an additional two ounces would cause the system to damage the compressor. There are fail safes to prevent excessive pressures. Two specs, one for
510 the other for 567 (grams) the difference of 57 grams is about 2 ounces.

 

[timtlu]

The two specs are within 2 ounces of each other. It is UNLIKELY that an additional two ounces would cause the system to damage the compressor. There are fail safes to prevent excessive pressures. Two specs, one for
510 the other for 567 (grams) the difference of 57 grams is about 2 ounces.

Full disclosure that I'm not an AC technician. But everything I've read states as little as 10% overcharge is likely to cause compressor failure. This is up for debate.

On the other hand I am pretty good at math. A 57g overcharge to an intended 510g capacity system is just over 11% overcharge. This is fact.

If you look at other vehicle refrigerant sticker tolerances you will find the accepted range of charge typically varies between 2% - 4%. A 11% overcharge would be somewhere between 2.5x (250%) to 5.5x (550%) over the accepted tolerance in these cases.






Or you could just take the common sense approach. Why would Ram take the time to update new specs of only 57g difference if that amount was too trivial to actually make a difference in how the mechanics of the cooling system work?

 

[Tom488]

Or you could just take the common sense approach. Why would Ram take the time to update new specs of only 57g difference if that amount was too trivial to actually make a difference in how the mechanics of the cooling system work?

Bean counters at work? At the cost of RF-1234YF of $4.50 per oz., at 500K trucks per year - $4.5M in savings?

 

[habfan]

I have a laramie loaner while one of our vehicles gets fixed
Yesterday it was a nice day but wanted to see how the A/C still worked in that weather the high was about 23C and dropped to be bit cool last night got to about 9C overnight.
When i started the truck up this morning I got a rush of hot air blowing onto me, I looked at the driver cluster and it showed the outside temp to be 15C.
The A/C was still on and set to 18.5 on the drivers side and 20C on the passenger side.
I pushed the button to turn off the A/C so it was just the fan and noticed the temp of the air blowing dropped, i then drove for a little and turned on the AC again and cool air was blowing and not the heated air. I suppose the cabin needed to heat up a bit.

kinda weird, as it makes me wonder if i'd rather have full control of the A/C and heat like i do in our little Mazda 3 that doesn't have auto climate control...

 

[timtlu]

Bean counters at work? At the cost of RF-1234YF of $4.50 per oz., at 500K trucks per year - $4.5M in savings?

I guess that's entirely possible. I'd prefer to think they would not want to put themselves in a position of creating a whole bunch of warrantied AC repairs, and tend to shy away from conspiracy theories altogether. Then again, I probably am a little over trusting in general.

If it is bean counting, why implement a change in the middle of the model year though? The timing seems to be much more likely a response to early failures they were finding.

Regardless, the absolute change between the old volume of 567g and new volume of 510g is more than nominal and pretty substantial (as far as my limited comprehension goes).

 

[DVARAM]

Well, dropped my Ram off at the dealer for a couple of issues this week, one of them was poor A/C performance. I realized I've had my A/C on "lo" temp and recirc almost since I bought it, which is not normal. I've also noticed that the air coming out of the vents when on non-recirc feels a bit humid/clammy. My best comparison was today, as I drove the base nissan loaner back to them and then my own truck home, the A/C in the Nissan felt better.

Dealer said "system was performing to spec" and I didn't have time to deal with them. It does look like they took the caps off the pressure lines under the hood. Any other ideas? Seems like I'm going to have to get a temperature probe and find another 2019 in person to do a side by side with. Trouble is, it isn't a deal-breaker, it isn't actually "broken", it just does not feel as good as my 2011 Ram. (or as any new high $ vehicle should)

Anyone have a way to find out what the temperature differential should be?

My service tech told me they are using a weaker coolant/freon in the 2019’s bc of new govt regulations.

 

[jimk hunt]

My service tech told me they are using a weaker coolant/freon in the 2019’s bc of new govt regulations.

And so is every other auto company. There are a ton of posts on the AC issue and it is definitely not related to the new refrigerant. Too many posts to read unless you have the issue or have been on here awhile. I used the hose clamp fix and am enjoying the AC again.

 

[Flot]

I'm the OP.

After a week of driving around, I'm confident to say that my last trip to the dealer has increased my A/C performance to reasonable modern vehicle levels. For the first time in a year I came out to my truck after it sat in 90 degree full sun for an hour, and I was comfortable 3-5 minutes after starting.

In my last service visit, the dealer indicated that they evac-ed and recharged the system, plus replaced the blower motor and fan assembly. (which had never given me any sign of trouble) They may or may not have done software updates, I suspect they did. I asked them to apply this and other TSBs, but there was no mention of any of them on the work order. (they also overinflated one tire to 40 psi and forgot to reset my oil change light, so these guys are not exactly detail oriented)

Will try to get confirmation from the dealer about exactly what they did when I return in a week for them to finish other items. I should be able to do some vent temperature tests this weekend.

 

[timtlu]

(they also overinflated one tire to 40 psi and forgot to reset my oil change light, so these guys are not exactly detail oriented)

Sweet! We use the same dealer!!!

 

[RBRK]

What is the correct sticker 510 ?

 

[Billet1500 4x4]

That depends on what your intended goal is. If you're only concerned about the temperature coming out of the vents, sure. If you actually care about the internal cabin temp, then you're only testing one piece of the entire puzzle. If you're looking at an equivalent volume of air, with the same circulation patterns, then the temperature is relative.

In other words, if the AC can't cool the volume of the cab, no matter how low the temp is coming from the vents, then the system is inadequate. If you're disabling parts of the system to get a front vent temp result, then I find it difficult to then conclude that the system is deficient.

I have experienced a notable difference in the cooling ability at idle with the fan vs. driving the truck. I wonder if there's something that FCA can change to improve function at idle, or if it's a limitation in the cooling area of the condenser affected by the round fan vs. the entire rectangular area cooled as the truck moves forward.

The limitation at idle is more related to compressor speed versus the fan speed. The compressor just doesn't have enough flow down at 600 RPM. That's why ram states to test the AC performance with the truck at 1000 RPM not at idle.

 

[Billet1500 4x4]

Is there a 12v variable valve that you can control remotely? I would like to able to control how much flow is restricted without having to pop the hood.

This is what you're after.
12V electric heater bypass valve with remote variable control from all the way open to completely closed and everything inbetween.

50-1555 - Heater Valve Kit | Bypass Style, Electronic Servo Operated

Old Air Products electronic bypass heater valve kit has everything you need to install bypass valve in your vintage vehicle.

www.oldairproducts.com

 

[ac1dd]

I'm the OP.

After a week of driving around, I'm confident to say that my last trip to the dealer has increased my A/C performance to reasonable modern vehicle levels. For the first time in a year I came out to my truck after it sat in 90 degree full sun for an hour, and I was comfortable 3-5 minutes after starting.

In my last service visit, the dealer indicated that they evac-ed and recharged the system, plus replaced the blower motor and fan assembly. (which had never given me any sign of trouble) They may or may not have done software updates, I suspect they did. I asked them to apply this and other TSBs, but there was no mention of any of them on the work order. (they also overinflated one tire to 40 psi and forgot to reset my oil change light, so these guys are not exactly detail oriented)

Will try to get confirmation from the dealer about exactly what they did when I return in a week for them to finish other items. I should be able to do some vent temperature tests this weekend.

Hello friend could you measure the vent temps for us? Run car for at least 15 minutes with AC on, in recirculate mode, on a medium blower fan setting. Thanks We're trying to get some at least rough scientific data together.

 

[technicholas]

Hello friend could you measure the vent temps for us? Run car for at least 15 minutes with AC on, in recirculate mode, on a medium blower fan setting. Thanks We're trying to get some at least rough scientific data together.

Do you work for RAM? I would be willing to help measure temps and show when its humid it works bad vs no humid.

 

[ColoradoCub]

Do you work for RAM? I would be willing to help measure temps and show when its humid it works bad vs no humid.

Well it’s never humid where I live and it still doesn’t perform for S@#t!

 

[technicholas]

Well it’s never humid where I live and it still doesn’t perform for S@#t!

If you pinch off the heater core you can't believe how cold it is.

 

[ColoradoCub]

If you pinch off the heater core you can't believe how cold it is.

Are you kidding.....I installed the valve mod the week I got my truck, that’s the only way the AC is tolerable!

 

[technicholas]

Are you kidding.....I installed the valve mod the week I got my truck, that’s the only way the AC is tolerable!

I drove two hours in it and my butt was cold from the cooled seats for the first time ever! LOL