Air conditioning freezing

[Repoman1]

About a month ago I had my ac evaporator replaced and ac recharged. It has been sucking for the last few yrs barely blowing. Ever since having it replaced, the ac line under the hood will freeze after 30 mins to an hour of driving causing the ac to stop blowing or barely blow. There are no leaks, had that checked, and even had the ac freon pulled out and put back in by a local dealership to make sure the correct amount, and weight, was installed. Ac still freezes up while driving. It doesnt do it while parked idling. Ambient temp outside has been running 91 to 95 degrees. When the ac lines aren't frozen the ac air temp coming from the vents is 48 - 50°. Ive installed a thermometer in the vents to measure the air temp. I have also replaced the temp sensor, the expansion block under the hood and the evaporator temp sensor in the dash. Anyone have this issue in the past and come across a solution? Had the AC lines evacuated and refilled at a local dealership. Went for a drive today and about 30 mintes into it the ac lines froze again. This time I pushed the AC button on the dash to turn off the AC but left the recirculation button on. After being off for about 45 secs to a minute I selected the AC button and the truck immediately started cooling off again. Im lost so is the ac guy. AC runs per the in dash thermometer right at 48 to 50 degrees and blows hard until it starts to freeze. The only thing that hasn't been replaced is the AC control board on the dash and the compressor. Compressor has been checked and functions correctly.

Anyone know of a sensor I maybe missing or someone who's had this issue and found the remedy?

Blend doors work perfect, nothing blocking the ac vents or intake, new cabin filter, ac freon been checked a few different times and there's no leaks.

2016 Ram 2500 Cummins 4 door

2016 Ram 2500 Lone Star Crew Cab Luxurious Brown Pearlcoat

 

[crash68]

If the refrigerant charge is correct, there's only about two things that could cause the evaporator coil to freeze. Either the low pressure control calibration is off and/or the metering device is malfunctioning(sounds like this has been replaced though). Being the system is designed for variable airflow that pretty much narrows what wrong back to the low pressure control. It's either letting the evaporator get too cold or not letting it warm up enough before turning back on. The service tech is going to need some good pressure gauges and it would be worth to check the performance of the metering device too.
Does the condensate drain properly from the HVAC system?

 

[oe542bob]

I had a 2003 3500 Laramie with the Cummins years ago. Same issue. It started after the heater box was replaced. Put everything back together with new blend doors. Dealership put the Freon back in and I thought great.
Then I started having the evaporator freezing up. I could tell right away as the air flow started to diminish and the cab temperature would get warmer.
Took it back to the dealership to confirm that the freon was right. They said it has the correct amount
Never did figure it out, but what worked for me was, leave the fan on, turn ac off for a minute or 2. You could tell when it cleared as the air was blowing fast. I then turned the ac back on and most of the times it would not freeze again.
It seemed to be worse on hot humid days.

 

[06 Dodge]

Did they check to see if the expansion vale is working properly, I had one stop working way back when they used R12, also proper compressor oil level, I assume they still use one on the modern A/C systems.

 

[Burla]

Did the use correct refridgerant or replacement? If they used YF they really screwed you.

 

[Burla]

Basically many shops are using butane and mixing it with great refridgerant making it impossible to capture.

watch this isht, crying shame!!!

This will blow your freaking mind fellas.

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Don't Buy R134a Refrigerant Until You Watch This!

Don't Buy R134a Refrigerant Until You Watch This!Are those cheap R134a replacement refrigerants worth it—or a disaster waiting to happen?In this video, we br...

youtu.be

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[Burla]

Mixing R134a and R1234yf refrigerants symptoms

Evaporator Freeze-Up:
.Opens in new tab
In systems that use pressure control for evaporator freeze protection, mixing refrigerants can disrupt the pressure balance, potentially causing the evaporator to freeze and reduce airflow

 

[turkeybird56]

Why? lol. They don’t mix or am I completely silly?

 

[Burla]

Why? lol. They don’t mix or am I completely silly?

Watch the video, every guy should.

 

[turkeybird56]

Watch the video, every guy should.

SIC, was tongue in cheek silly BOIRD humor. I am aware U do not mix refrigerants and/or should not mix Radiator type fluids also, LOL.

 

[Burla]

SIC, was tongue in cheek silly BOIRD humor. I am aware U do not mix refrigerants and/or should not mix Radiator type fluids also, LOL.

Yes it is bad because "they" call it r134 replacement, so this stuff is getting mixed out there, even says e134 on the bottle so this is planned out.

 

[turkeybird56]

Yes it is bad because "they" call it r134 replacement, so this stuff is getting mixed out there, even says e134 on the bottle so this is planned out.

Good way to F-ubar whole AC system. Clam up drier, evaporator etc. Ppl gotta be smarter than all the BS hype out there.

 

[Tominator223]

If they put the wrong oil in the system , it can cause what we used to call Black Death. It would create a black like rock that was usually at the condenser by the low pressure line . This would cause all kind of weird conditions. Sometimes you’d get lucky take the line of at condenser & you could get it out. Sometime you couldn’t & a new condenser was needed. Also the butane charge has been around since the R-12 days. When R-12 got to be about $60 a 12oz can you could get the butane-12 for about $8 a can. & it worked in R-12 systems no prob. I did a few car lot cars with it. R-12 is now like over $1000.00 a lb.

 

[Repoman1]

If the refrigerant charge is correct, there's only about two things that could cause the evaporator coil to freeze. Either the low pressure control calibration is off and/or the metering device is malfunctioning(sounds like this has been replaced though). Being the system is designed for variable airflow that pretty much narrows what wrong back to the low pressure control. It's either letting the evaporator get too cold or not letting it warm up enough before turning back on. The service tech is going to need some good pressure gauges and it would be worth to check the performance of the metering device too.
Does the condensate drain properly from the HVAC system?

The tech has use 2 different sets of guages to make sure it was within spec. The drain is also working well. It's pouring water out.

 

[Repoman1]

I had a 2003 3500 Laramie with the Cummins years ago. Same issue. It started after the heater box was replaced. Put everything back together with new blend doors. Dealership put the Freon back in and I thought great.
Then I started having the evaporator freezing up. I could tell right away as the air flow started to diminish and the cab temperature would get warmer.
Took it back to the dealership to confirm that the freon was right. They said it has the correct amount
Never did figure it out, but what worked for me was, leave the fan on, turn ac off for a minute or 2. You could tell when it cleared as the air was blowing fast. I then turned the ac back on and most of the times it would not freeze again.
It seemed to be worse on hot humid days.

That's the same sequence Im using now to keep the line from freezing. As soon as I feel the air pressure change from the vents Ill turned off the recirculation and run only the fan for about 30 to 45 secs.

 

[Repoman1]

Did the use correct refridgerant or replacement? If they used YF they really screwed you.

They used what it required from the factory. The trucks a 2016