[greentraverse]

So if you're following me, I just replied to Megan this morningregarding her AC issue. I explained to her how the compressor supplies both front and rear evaporators and a quick explanation of the actuators. I mentioned that I was having an intermittent issue with my actuators, but hadn't checked them yet.

Here's the story: About a month ago, I started car and got about 10 secs of a squeal coming from the dash, couldn't tell exactly where. After that, the passenger side AC doesn't get cold. It gets "cool," but not as cold as the drivers side. A day or two later, it's OK again. Then it's bad again. So it's been off and on, with more off than on, ever since. As I told Megan, I thought it might be the passenger side temperature actuator, but I hadn't checked it yet. So now I've shamed myself into checking it. (I did pull the fuse and let it recalibrate a week or so ago, but that didn't change anything.)

So this afternoon, I observed the mode actuator on the passenger side move full range while swapping from vent to floor to bilevel to defrost and I observed the recirc actuator move full range for outside air and recirc. I observed the passenger side temperature actuator move full range from hot to cold, but it never gets as cold at the driver side. I couldn't understand why the passenger side wouldn't get cold if the actuator is moving full range, so even though it's a PITA, I pulled the actuator and verified that I could physically move the damper myself. I can actually hear and feel the damper go closed in the cold position, but still get only "cool" air.

So I'm wondering how in the heck can the damper be moving fully to the cold position, but I'm only getting cool air, not cold air?

Anybody have any thoughts?

 

[Revpeach1]

I had a similar problem with my 2015 LTZ. I also had the pin hole leak in the rear evaporator line which means about once a year I have to give it a shot of freon. After I top off the freon the driver's side and passenger side return to equal coolness.

 

[greentraverse]

Thanks for the info. I don't know why low refrigerant would only affect one side and not the other, though.

 

[repairman54]

With low ''Freon'' the evaporator only gets cold partially so depending on how air is directed through it will change how air gets cooled. If D side air flow is next to the evap. inlet it will be colder.
Having one apart to see how it works would make it easy but that's a lot of work for sure.

 

[greentraverse]

Looks lie a recharge can is around $35, so I'll give it a try today.

I don't know what the squeal was. Do these things have relief valves if the pressure gets too high?

 

[cintocrunch]

Get the one with the dye in it so it's easier to track down the leak if a more substantial repair is needed down the road.

 

[repairman54]

Quikie cans usually have gauges and adapter for the low side.
If high side is too high PCM will turn off the compressor.

 

[greentraverse]

Charged with R-134A until in the green. Didn't seem to help.

 

[rbarrios]

hmmm.
May want to remove the glove box and drop the blower fan.
There is supposed to be a screen to filter out stuff from the inlet.
Im wondering if something has gotten in past the screen and maybe clogged one of the passages to the side that is acting up.

 

[Revpeach1]

I've noticed on mine that at start up the driver's side is cooler and as the car interior begins to cool it then equals out onto the passenger side.

 

[greentraverse]

hmmm.
May want to remove the glove box and drop the blower fan.
There is supposed to be a screen to filter out stuff from the inlet.
Im wondering if something has gotten in past the screen and maybe clogged one of the passages to the side that is acting up.

I'd think that would change the air flow. Flow seems unchanged, just not cool. Won't have time to deal with it for awhile, but maybe I'll try it later.

 

[Markuendo]

I'd think that would change the air flow. Flow seems unchanged, just not cool. Won't have time to deal with it for awhile, but maybe I'll try it later.

Did you find a resolution?

Out of curiosity, do the back vents cool as much as the driver side does?

Sent from my SM-G965U using Tapatalk

 

[greentraverse]

No I haven't found a solution. I did pull the passenger side actuator and verified it was working and the damper was free to move. Also eyeballed the other actuators and verified they were moving. Too cold out now to mess with it. Not sure about the rear, but I don't think it's cooling much either. So it might be a problem with the refrigerant or maybe even the compressor. But the initial squeal seemed to come from the center stack, which led me to think the actuators.

 

[Markuendo]

I've had a couple of vehicles one 2012 Acadia another 2002 Chevy venture that had a similar issue when there was a charge related problem. Like you said maybe it was a compressor or something.

If memory served, when there was an issue, the back air conditioning warned up then eventually the passenger side. Driver side was always sort of the last to go which was hard to notice when that's where you sit

Sent from my SM-G965U using Tapatalk

 

[ekimmike]

So if you're following me, I just replied to Megan this morningregarding her AC issue. I explained to her how the compressor supplies both front and rear evaporators and a quick explanation of the actuators. I mentioned that I was having an intermittent issue with my actuators, but hadn't checked them yet.

Here's the story: About a month ago, I started car and got about 10 secs of a squeal coming from the dash, couldn't tell exactly where. After that, the passenger side AC doesn't get cold. It gets "cool," but not as cold as the drivers side. A day or two later, it's OK again. Then it's bad again. So it's been off and on, with more off than on, ever since. As I told Megan, I thought it might be the passenger side temperature actuator, but I hadn't checked it yet. So now I've shamed myself into checking it. (I did pull the fuse and let it recalibrate a week or so ago, but that didn't change anything.)

So this afternoon, I observed the mode actuator on the passenger side move full range while swapping from vent to floor to bilevel to defrost and I observed the recirc actuator move full range for outside air and recirc. I observed the passenger side temperature actuator move full range from hot to cold, but it never gets as cold at the driver side. I couldn't understand why the passenger side wouldn't get cold if the actuator is moving full range, so even though it's a PITA, I pulled the actuator and verified that I could physically move the damper myself. I can actually hear and feel the damper go closed in the cold position, but still get only "cool" air.

So I'm wondering how in the heck can the damper be moving fully to the cold position, but I'm only getting cool air, not cold air?

Anybody have any thoughts?

Did you ever find an answer? I am having the EXACT same problems. Actuator moves normally but only gets cool

 

[greentraverse]

No. I think I'm out of refrigerant, but haven't been able to get it into to someone who knows what they're doing. I tried adding it myself, but apparently was unsuccessful. It hisses sometimes now, which I think is a sign of not enough refrigerant. When I park on my daughters driveway, which is at about a 30 degree uphill, it seems to suddenly do some cooling. I don't know if I have a leak or something else is going on. I know very little about automotive AC systems, but I would assume it has some sort of pressure relief valve (most high pressure systems do); maybe it opened prematurely?

 

[greentraverse]

A few months ago I tried adding refrigerant myself. Didn't seem to take it. Then I was out of town and unable to do anything else until this week.

Today I finally got the opportunity to take it to an auto place (101 deg F today, too!) and let someone that knows what they're doing look at it. They added coolant and it's blowing cold again. They added a dye and I need to take it back next week for them to try to see the leak. The most popular leaks here on the forum seem to be the lines to the rear AC getting damaged, and an AC hose in the engine compartment that rubs on something. I'm hoping it's the latter, as I suspect that will be cheaper.

 

[repairman54]

Rear lines corrode in the salt zone over time. Just got my Tahoe out of the dealer yesterday for a rear a/c line replacement.
Had them done not quite 2 years ago. To my surprise they warrantied it. Everything. GM 2 yr. unlimited mileage warranty on the parts. No charge even for 134 or oil, totally free.
And dealer's suck? no independent shop would give a 2 yr complete warranty on that job, which is a bear, I did those lines myself on my '99 Yukon.

 

[greentraverse]

So I took it back in yesterday so they could look for signs of leakage. They couldn't find any. It's still blowing cold, so I guess I'll sit tight until it loses its charge again.

 

[L2W]

So if you're following me, I just replied to Megan this morningregarding her AC issue. I explained to her how the compressor supplies both front and rear evaporators and a quick explanation of the actuators. I mentioned that I was having an intermittent issue with my actuators, but hadn't checked them yet.

Here's the story: About a month ago, I started car and got about 10 secs of a squeal coming from the dash, couldn't tell exactly where. After that, the passenger side AC doesn't get cold. It gets "cool," but not as cold as the drivers side. A day or two later, it's OK again. Then it's bad again. So it's been off and on, with more off than on, ever since. As I told Megan, I thought it might be the passenger side temperature actuator, but I hadn't checked it yet. So now I've shamed myself into checking it. (I did pull the fuse and let it recalibrate a week or so ago, but that didn't change anything.)

So this afternoon, I observed the mode actuator on the passenger side move full range while swapping from vent to floor to bilevel to defrost and I observed the recirc actuator move full range for outside air and recirc. I observed the passenger side temperature actuator move full range from hot to cold, but it never gets as cold at the driver side. I couldn't understand why the passenger side wouldn't get cold if the actuator is moving full range, so even though it's a PITA, I pulled the actuator and verified that I could physically move the damper myself. I can actually hear and feel the damper go closed in the cold position, but still get only "cool" air.

So I'm wondering how in the heck can the damper be moving fully to the cold position, but I'm only getting cool air, not cold air?

Anybody have any thoughts?

FYI for anyone else who it might help. My 2013 a few years ago stopped blowing cold air in the back. A few years later, passenger side started blowing warm while drivers was cold. Then a few years later, drivers side went warm too. Dealer freaked me out saying it might cost $3K. I spent $60 ($25 of which for a 2 foot hose extension) and recharged the refrigerant myself. That fixed ALL vents. All cold now. So my issue of low refrigerant mimicked actuators going bad.