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AC Fix TSB (Pre 8/20 build trucks)

boatdude1 said:
My truck was done a couple of weeks ago. Huge difference. More air volume for heat and A/C and the air is much colder .
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More volume would be a big plus for me.
 
Is this affecting new trucks....2021's?

Sent from my moto z3 using Tapatalk
 
Finally after almost 4 weeks my dealership did the TSB in my 5500, going to pick it up today. I'll see how it goes, my 2019 2500 has not had the TSB done yet so i'll be able to directly compare blower force. Temperature comparison is gonna have to wait until the polar vortex leaves NJ.
 
can't comment on how cold the AC blows, but i will say the new TSB blower in the 5500 pushes A LOT more air than the original blower in my 2500. I would say the new TSB blower on 4 is about the same as the original blower on 7.
 
My 2019 A/C was fixed. I have posted this information in a few other forum threads, but somehow I overlooked this thread. Most of the regular forum members already know all of this information, so sorry if it is a rehash to you.

Before the fix, I experienced two major problems:
1. The HVAC would not blow equal temperatures out of the driver and passenger vents. I made a YouTube video showing the problem.
2. The HVAC would blow inconsistent temperatures at weird times. For example, I would have the heat on a high (but not max) setting, but the HVAC would suddenly blow cold air. Or, I would have it on a high cooling setting, but the HVAC would suddenly blow hot air.

After the dealer installed all of the updated HVAC components, I am not experiencing either of the problems, although it hasn't been hot enough for me to try the air conditioning. Everything works as expected with the heater.

The repair should take 7 hours, but this was the first time my dealership has performed this repair, so it took them 3 work days. They said they went slowly and were very careful, but they did slightly scratch a piece of my dashboard, They found the scratch and replaced the part voluntarily.

Overall, I am very happy with the fix. I appreciate what @RamCares did to help push this fix through the engineering and warranty departments.

Here are the parts that were replaced. They also had to drain/refill all of the engine coolant, so I got a free coolant flush.



IMG_3147 (1).jpg
 
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What’s the procedure for checking the vents?

I know we’re looking for consistent temps across the dash vents, but are we looking for a certain temp drop below ambient?

Last summer I felt like my a/c was not as good as I wanted it to be, but I was coming from a king ranch so I didn’t really think too much about it.
 
Rockcrawlerdude said:
What’s the procedure for checking the vents?

I know we’re looking for consistent temps across the dash vents, but are we looking for a certain temp drop below ambient?

Last summer I felt like my a/c was not as good as I wanted it to be, but I was coming from a king ranch so I didn’t really think too much about it.
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On an 83 degree (F) day, I measured 7 degrees difference in temperature between the driver's right vent and the passenger's left vent. Here is a video showing how I measured the temperature. Skip to the 6:13 mark if you just want the results.

 
Interesting video showing the discrepancies with the air temps. It seems like an easy fix installing the valve, but (me) not knowing anything about the flow of coolant thru the vehicle system, does closing that valve off have a detrimental effect on the entire system flow?
 
steve49 said:
Interesting video showing the discrepancies with the air temps. It seems like an easy fix installing the valve, but (me) not knowing anything about the flow of coolant thru the vehicle system, does closing that valve off have a detrimental effect on the entire system flow?
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You don't need to install the valve. I just did that to demonstrate how the coolant flowing inside HVAC ducting is interfering with the A/C temperature. You can just measure the temperature differential between the driver's side and passenger's side air vents to show your dealership that you are experiencing the symptom in the TSB.
 
If one truck is bad and they have to change out the entire HVAC box, that means that ALL are bad. I guess that I need to find out if the dealer will do the TSB without symptoms. I checked mine today, but I think I need to get it up to temp to see if the problem is there. We have had the truck since May of 2019 and because of Covid, it only has 2100 miles on it.
 
Phil T said:
If one truck is bad and they have to change out the entire HVAC box, that means that ALL are bad. I guess that I need to find out if the dealer will do the TSB without symptoms. I checked mine today, but I think I need to get it up to temp to see if the problem is there. We have had the truck since May of 2019 and because of Covid, it only has 2100 miles on it.
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I agree. This is a design defect that is fixed by replacing the HVAC ducts and control module. There is no need for the dealership to do any troubleshooting on a truck that is covered by the TSB. The TSB even states, " DIAGNOSIS:
If the customer describes the symptom/condition listed above, perform the Repair Procedure."
 
My 2020 / 3500 HO has 20K with a build date of 1/20 on it and it works great in the AZ temps. No issues with it being cold.
 
I finally got mine back after getting the TSB done on Friday. Honestly it was only 85° Out so it’s hard to tell the difference. I threw some thermometers on it just to see it was getting maybe 55° air which i don't think is much different than when I had before but time will tell when Arizona hits 110. I don’t really notice much difference in the blower speed which is interesting. But what the hell I figure worst-case I’ll just clamp the heater core again.
 
jakalafus said:
I finally got mine back after getting the TSB done on Friday. Honestly it was only 85° Out so it’s hard to tell the difference. I threw some thermometers on it just to see it was getting maybe 55° air which i don't think is much different than when I had before but time will tell when Arizona hits 110. I don’t really notice much difference in the blower speed which is interesting. But what the hell I figure worst-case I’ll just clamp the heater core again.
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How reputable is the dealer you went to? I wonder if they just topped off the freon and said yeah we put in the 8 hours labor to do your free tsb.

The blower force between the 5500 at my work that had the tsb done vs my 2500 which didn't is pretty significant.
 
I just scheduled my long list of service needs including this with the dealer online. Two weeks out just to get in, and I'm sure it will then be another few weeks to get the HVAC TSB completed.
 
jakalafus said:
I finally got mine back after getting the TSB done on Friday. Honestly it was only 85° Out so it’s hard to tell the difference. I threw some thermometers on it just to see it was getting maybe 55° air which i don't think is much different than when I had before but time will tell when Arizona hits 110. I don’t really notice much difference in the blower speed which is interesting. But what the hell I figure worst-case I’ll just clamp the heater core again.
Click to expand...

What is the temperature differential between the driver's right vent and the passenger's left vent? 55 seems high.

Also, were you experiencing the problem with the HVAC blowing weird temperatures when not set on max heat or max cooling? Mine (and @g00fy) both had problems with the temperature fluctuations, but I am no longer experiencing that problem.
 
I just got back from lunch and took the truck to check the temps. With the AC set to 68 degrees and the air only at the top, 82 on the passenger side, 110 on the drivers center. Houston we have a problem. I will be contacting the dealer to schedule and order the parts tomorrow.
 
thestuarts said:
What is the temperature differential between the driver's right vent and the passenger's left vent? 55 seems high.

Also, were you experiencing the problem with the HVAC blowing weird temperatures when not set on max heat or max cooling? Mine (and @g00fy) both had problems with the temperature fluctuations, but I am no longer experiencing that problem.
Click to expand...
Temps are consistent across all the vents now at least. I don’t remember weird temps on max heat. But looking back at my notes 55 is about 10 degrees cooler than what i got during summer on max AC previously. My dealer is a good dealer and i can tell they did something....
 
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