AC freeze-up

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elc32955
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AC freeze-up

Post by elc32955 »

OK, here's some weirdness. I was driving a 2015 LFX car, 103K miles, recent auction purchase to take the car to the new owner. About an 1100 mile roadtrip split over 2 days. Day 1, AC worked fine during the day, however in evening driving the air quantity coming out of the vents went lower speed, and lower... and even more lower. I cranked up the fan speed to 12 and the fan was spinning like mad, but hardly any air flow. I would get brief bursts of air, but for all intents it was blowing at about a 1 speed, if that fast. Condensate drain couldn't be checked as it was after dark when this started.

Day 2 - Started it up about 9:30 AM, AC was fine. Condensate was a-flowin' out of the drain fine. Worked all day & night just peachy.

So... I had originally hypothesized it might be a blocked cabin filter keeping the air from flowing, but it worked fine all day on Day 2. Sounds like the system may have iced up from what I'm guessing. This AC works VERY efficiently in the arctic breeze department. Ambient outside on Day 1 was in the 70's tops, Day 2 was mid 90's.

Thoughts anyone?

Thanks
Eric
System Manager and your tour guide for the day. 2015 Caprice w/LFX, former NC DPS staff car. Partial hybrid G8/SS/Camaro SS interior mods, SS MyLink radio upgrade, 2016 Camaro V6 rims, GMPP Malibu chrome exhaust tips, otherwise bone stock for now.
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Mooseman
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Re: AC freeze-up

Post by Mooseman »

You may be low on refrigerant or have a faulty low pressure switch that doesn't switch off the compressor when you have low pressure, or both. You would need a gauge set to see what pressures you are getting.
2011 Caprice PPV, former RCMP test vehicle, never put into service
Build Thread: http://www.newcaprice.com/forum/viewtopic.php?t=2419
Sanford
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Re: AC freeze-up

Post by Sanford »

I am assuming the 14-17’s have similar HVAC strategies as the 11-13’s. I would get into the HVAC module with scanner and take a look at the evap core temp, to see if the evap temp sensor is showing a below freezing temp. With a variable displacement compressor, troubleshooting one of these things can get interesting. Could be an evap core that is packed with crap from running it on recirculating all of the time, since that air is not filtered. Lots of possibilities on this one.
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elc32955
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Re: AC freeze-up

Post by elc32955 »

Roger that, thanks!! I passed this along to the new owner. We're going to pull the cabin filter later today & clean out that plenum, might be a good indication of how much junk may have infiltrated. And also toss it on the scanner for a read. Just keeping my fingers crossed it was a fluke as this car had been sitting for a while before... Zoooomie! 1100 miles across country in one sitting.

Thanks
Eric
System Manager and your tour guide for the day. 2015 Caprice w/LFX, former NC DPS staff car. Partial hybrid G8/SS/Camaro SS interior mods, SS MyLink radio upgrade, 2016 Camaro V6 rims, GMPP Malibu chrome exhaust tips, otherwise bone stock for now.
96accord
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Re: AC freeze-up

Post by 96accord »

elc32955 wrote: Sun Jun 04, 2023 10:54 am Roger that, thanks!! I passed this along to the new owner. We're going to pull the cabin filter later today & clean out that plenum, might be a good indication of how much junk may have infiltrated. And also toss it on the scanner for a read. Just keeping my fingers crossed it was a fluke as this car had been sitting for a while before... Zoooomie! 1100 miles across country in one sitting.

Thanks
Eric
I'm new here (as you know) but is the new owner a friend or you just deliver Caprice's to people as a job?
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elc32955
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Re: AC freeze-up

Post by elc32955 »

Nope, delivering the car for a good friend's business. He had an auto transporter contracted to make the run, but.....BZZZZZ - no show on the company. So this was a Hail Mary play to get the car

Eric
System Manager and your tour guide for the day. 2015 Caprice w/LFX, former NC DPS staff car. Partial hybrid G8/SS/Camaro SS interior mods, SS MyLink radio upgrade, 2016 Camaro V6 rims, GMPP Malibu chrome exhaust tips, otherwise bone stock for now.
s/c'd cav
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Re: AC freeze-up

Post by s/c'd cav »

some cars will get ice build up on the evaporator , depending on the outside weather conditions , i had mine freeze up a few times on a road trip , usually happens more on medium to slower fan speeds

just turn the a/c off for a few , and youll feel the air speed increase out of the vents

my old cavalier used to do the same thing
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