No A/C (pics included) 06 Denali XL 6.0L

[h2osho]

Well of course my A/C goes out the week it's 90 in Michigan and could hit 100 today. Last month I used 2 cans of r134a and my air worked fine. Well it's quickly dying and now is blowing warm. The compressor turns on so I know there's a couple pounds in the system. I do not have gauges. Well, I went to put some freon in the system and I noticed that on the low side the tube was COLD and the other side of the connector on the high side the tube is HOT.

I also noticed a drip, which could be condensation since it's humid out. I swear I hear a hiss or leak, but it could be my mind. I don't want to put more freon in the system if it doesn't need it and something is plugged or leaking?

Doesn't matter if I run my AC on AUTO or High or whatever nothing changes.

Any ideas would be appreciated.

 

[PG01]

Ould be you blend door actuator, get under the dash and switch it from hot to cold a few times and see and listen whats going on. Most of those kits from auto parts dtore have a gauge, while they aren’t the best theyll give you an idea where the charge is at. It also could be the orifice tube is clogged not letting charge circulate... which requires work.... need to capture whatever is in the system, swap parts put it back together, make sure it holds a vacuum then charging it back up. Do you have rear a/c? Those lines runn down the passenger side of the truck and sometimes get damaged from underneath. Uses same compressor the ac lones are just t’ed off of front lines. If you hear compressor and rear air (if you have it) works, either the controller or blend door are your problem. Im not an a/c guy so im throwing ideas out at you

 

[h2osho]

Ould be you blend door actuator, get under the dash and switch it from hot to cold a few times and see and listen whats going on. Most of those kits from auto parts dtore have a gauge, while they aren’t the best theyll give you an idea where the charge is at. It also could be the orifice tube is clogged not letting charge circulate... which requires work.... need to capture whatever is in the system, swap parts put it back together, make sure it holds a vacuum then charging it back up. Do you have rear a/c? Those lines runn down the passenger side of the truck and sometimes get damaged from underneath. Uses same compressor the ac lones are just t’ed off of front lines. If you hear compressor and rear air (if you have it) works, either the controller or blend door are your problem. Im not an a/c guy so im throwing ideas out at you

Thanks for the ideas. It's 93 and muggy as h*ll so I might wait now until evening to get under that dash!

 

[Doubeleive]

if the condenser is warm then it's not the blend door simple check, condenser should be cold

 

[M1Gunner]

Temperature directly relates to pressure. High pressure equals high heat and low pressure equals colder temps. Condenser is on the high side so condenser will be hot, the evaporator is on the low side and should be cold. That being said the the 81 degrees your getting should be WAY lower than that. High 30’s low 40’s approx. and the high side should be approx 220 ball park.

 

[h2osho]

if the condenser is warm then it's not the blend door simple check, condenser should be cold

The condenser is ice cold. I stopped in the local O'Reiley's but they don't have gauges the public can use, so I might have to buy some. Could something be plugged???

 

[Doubeleive]

The condenser is ice cold. I stopped in the local O'Reiley's but they don't have gauges the public can use, so I might have to buy some. Could something be plugged???

I don't know I was just under the assumption that if the collector/condenser is cold then the system should be working and it may then be a blend door, if it was warm to the touch then it would likely be a bad pump or depleted Freon from a leak or broken line, etc. there could of course be some other issue going on, but if you want to check the actuator blend doors there is a kick panel under the passenger side dash~glove box, it has 3 or 4 bolts I think they are 7mm or 8mm, the one farthest under the center console is kind of a pain to get to but once you have that panel off you can see a couple of the door actuators, on the actuator is a hole with a round metal rod with a slot in it, that slot will rotate when the actuator is commanded from hot/cold, left/right, up/down etc. if you watch it and change the ac control you will see it move, if nothing moves then that may be the problem. there is another actuator but it is way up under the dash and is a fairly major job to get to but that one doesn't fail very often.

 

[sumo]

Without gauges hard to say. But since you don’t know how much wasnin the system, and you added 2 cans worked fine and now it isn’t 2 possible things come to mind. You have a leak in the system, condenser or the popular rear ac line above the Right rear tire or you overcharged your system and part of the system froze up. I suggest having the system evac and recharged with dye so you know everything is where it should be. If it gets warm again you could use a UV light to track down the leak

 

[h2osho]

Without gauges hard to say. But since you don’t know how much wasnin the system, and you added 2 cans worked fine and now it isn’t 2 possible things come to mind. You have a leak in the system, condenser or the popular rear ac line above the Right rear tire or you overcharged your system and part of the system froze up. I suggest having the system evac and recharged with dye so you know everything is where it should be. If it gets warm again you could use a UV light to track down the leak

Sadly I think that might be my answer. Or I start looking at trading her in, there's a couple other things that need attention. I just love the Denali XL, it rides like a dream.

 

[h2osho]

Without gauges hard to say. But since you don’t know how much wasnin the system, and you added 2 cans worked fine and now it isn’t 2 possible things come to mind. You have a leak in the system, condenser or the popular rear ac line above the Right rear tire or you overcharged your system and part of the system froze up. I suggest having the system evac and recharged with dye so you know everything is where it should be. If it gets warm again you could use a UV light to track down the leak

Well the cheap Walmart gauge told me it was full. So I didn't add any. Earlier I checked the condenser and it felt cold, but after 2 minutes it heated right up. So my system doesn't leak, something simply isn't working properly.

 

[PG01]

I think yer orifice is clogged.........or maybe blend door

 

[M1Gunner]

Well the cheap Walmart gauge told me it was full. So I didn't add any. Earlier I checked the condenser and it felt cold, but after 2 minutes it heated right up. So my system doesn't leak, something simply isn't working properly.

View attachment 202712 View attachment 202713

Well what you’re pointing at is the accumulator and that lil fella should most definitely NOT be anywhere close to 100 degrees unless your system is not even on and that’s ambient temp.

 

[sumo]

Well the cheap Walmart gauge told me it was full. So I didn't add any. Earlier I checked the condenser and it felt cold, but after 2 minutes it heated right up. So my system doesn't leak, something simply isn't working properly.

View attachment 202712 View attachment 202713

That’s just a lo side. With a good gauge set you can see what the readings are with the system running. What about high side? If you had to add 2 cans as stated, there’s a leak. If there’s no leak, then you overcharged it. There’s multiple reasons why ac won’t work. Electrical problem like relay, pressure sensor, compressor coil, faulty hvac control unit
Mechanical, compressor clutch, seizing compressor.

 

[RonnieMc]

I hope it's not like my 2005 Yukon XL Denali that I bought here in KY about a year ago as a local trade in. I didn't do enough research on the VIN to find out it was bought and spent most of it's life in PA. My air went out and I took it to a racing buddy of my that has a complete shop that he owns and he checked it out with the leak detector and found the rear evaporator coil was bad and the line going to it had completely corroded in two. To replace the line, the body has to be raised up. He talked with a GM engineer that as soon as he described the problem said the car had come from up north with the road salt eating the lines up. He also said that GM had a problem with the blower motor in the rear blowing brass particles ( a brass bushing for the motor ? ) into the aluminum core reacting to cause failure. I'm still waiting to get it back.

 

[h2osho]

Well after trying numerous things and finding a good video on Youtube about resetting your AC (pulling the fuse and other things), nothing worked. I've been messing around with trading in the Black Beast, and I finally did it. Thanks to everyone who helped with an idea, but the ride is gone. I picked up a 2012 GMC Acadia Denali, and now another chapter in my long line of GMC products.

 

[M1Gunner]

Well after trying numerous things and finding a good video on Youtube about resetting your AC (pulling the fuse and other things), nothing worked. I've been messing around with trading in the Black Beast, and I finally did it. Thanks to everyone who helped with an idea, but the ride is gone. I picked up a 2012 GMC Acadia Denali, and now another chapter in my long line of GMC products.View attachment 202824

I hate to say it BUT those year gm’s are prone to having condenser problems. 12-15ish gm’s trucks and suvs those condenser blow out approx 30-50k miles

 

[06JET]

Nice new ride. Congrats.