AC problem

[2010gmcyukon]

I've search around here a bit and followed some advice on other posts, but haven't been able to find this exact problem. Any advice is appreciated.

I have a 2010 Yukon SLT, 5.3L, 100k miles. It has the auto climate controls. I bought it back in Feb this year . This is the first time it's been warm enough to need AC. Both front and rear are only blowing warm air. All controls on the console work as far as dash/vent/floor, fan speed, heat, etc. It does not matter if I have it set to auto, ac, or recirculate, or what temp I set it on. The air is always warm.

Here's what I've checked so far:
Compressor engaged and runs fairly consistenly when AC is on.
The accumulator/drier under the hood is cold to the touch.
I stuck a recharge kit/gauge on it and it reads full
I blew out the 2 sensors on the headliner.
I replaced the blend door actuator under the passenger side dash. This did not make a difference.
I also recalibrated the system (remove ac fuse, start, shut off, etc). The system had set itself to 74degrees when complete, so I believe I did that correctly.

A side note, possibly related, when it got really cold back(around 0 degrees f) in February there were a few days when my defrost and heat would not come on at all. No air coming from the vents or dash as all. the heat/defrost was working fine before this. Once the temp warmed up a bit it started working. By the time the shop looked at it, weather had warmed up and could not reproduce the issue.

 

[04BUCKET]

I HAD A DEALERSHIP LOOK AT MY TAHOE FOR A WARM AIR ISSUE AS WELL. COULDN'T FIND ANY ISSUES AND ARE RECOMMENDING A COMPRESSOR REPLACEMENT. HAVEN'T DECIDED IF I NEED AC THAT BAD YET...

 

[2010gmcyukon]

I HAD A DEALERSHIP LOOK AT MY TAHOE FOR A WARM AIR ISSUE AS WELL. COULDN'T FIND ANY ISSUES AND ARE RECOMMENDING A COMPRESSOR REPLACEMENT. HAVEN'T DECIDED IF I NEED AC THAT BAD YET...

I would gladly pay for a new compressor if I knew that was the problem. But yeah that's an expensive guess.

 

[04BUCKET]

I AGREE...PAYING FOR IT ISN'T THE ISSUE....AN EDUCATED GUESS IS THE ISSUE.

THAT BEING SAID....NO OTHER OPTIONS LEFT....AT LEAST AN AT COST DELCO ONE IS BETTER THAN NOTHING.

 

[Doubeleive]

I've search around here a bit and followed some advice on other posts, but haven't been able to find this exact problem. Any advice is appreciated.

I have a 2010 Yukon SLT, 5.3L, 100k miles. It has the auto climate controls. I bought it back in Feb this year . This is the first time it's been warm enough to need AC. Both front and rear are only blowing warm air. All controls on the console work as far as dash/vent/floor, fan speed, heat, etc. It does not matter if I have it set to auto, ac, or recirculate, or what temp I set it on. The air is always warm.

Here's what I've checked so far:
Compressor engaged and runs fairly consistenly when AC is on.
The accumulator/drier under the hood is cold to the touch.
I stuck a recharge kit/gauge on it and it reads full
I blew out the 2 sensors on the headliner.
I replaced the blend door actuator under the passenger side dash. This did not make a difference.
I also recalibrated the system (remove ac fuse, start, shut off, etc). The system had set itself to 74degrees when complete, so I believe I did that correctly.

A side note, possibly related, when it got really cold back(around 0 degrees f) in February there were a few days when my defrost and heat would not come on at all. No air coming from the vents or dash as all. the heat/defrost was working fine before this. Once the temp warmed up a bit it started working. By the time the shop looked at it, weather had warmed up and could not reproduce the issue.

so when you command it to 60 it only blows warm air? if so take a look at the blend door actuator (visibly) and see if it is all the way switched to cold or if it is only staying centered, if it is turned all the way and the ac only gets luke cold then you have a compressor problem or something clogged or condenser issue etc.

 

[04BUCKET]

LAST VISIT THEY WERE OPERATING CORRECTLY AND BLOWING NOT SO COLD AIR....MAY JUST HAVE TO BITE THE BULLET....

 

[2010gmcyukon]

so when you command it to 60 it only blows warm air? if so take a look at the blend door actuator (visibly) and see if it is all the way switched to cold or if it is only staying centered, if it is turned all the way and the ac only gets luke cold then you have a compressor problem or something clogged or condenser issue etc.

Yes, even when temp is turned all the way down it does not change the air temp. I did try replacing the blend door actuator under the passenger side dash, but it didn't make any difference. Not sure if there are more than one of them?

 

[Doubeleive]

Yes, even when temp is turned all the way down it does not change the air temp. I did try replacing the blend door actuator under the passenger side dash, but it didn't make any difference. Not sure if there are more than one of them?

I understand you replaced it, but...did you watch it turn to cold and stay there? there may be a left and right blend (maybe) for the front, the rear will only have one blend door

 

[2010gmcyukon]

I understand you replaced it, but...did you watch it turn to cold and stay there? there may be a left and right blend (maybe) for the front, the rear will only have one blend door

I don't know which side is cold, but I'll take another look to see if it rotates at all when I switch it from heat to cold.

 

[DaRosa218]

Did you re-calibrate the blender door position? My blender door was acting up and was able to re-calibrate via my tech-2 scanner. Unfortunately my AC system still is in protection mode and will not engage my AC compressor.

 

[2010gmcyukon]

Did you re-calibrate the blender door position? My blender door was acting up and was able to re-calibrate via my tech-2 scanner. Unfortunately my AC system still is in protection mode and will not engage my AC compressor.

I did these recalibration steps based on comments on this video. It did reset to 74 degrees, so hopefully that means I did it correctly.

1. Turned on ignition to accessory and set the heating system to AUTO. It does not matter what the temperature settings are when you do this, just that the system is set to automatic. I suggest you do set the temp of the system to any temperature other than 74 degrees as this is the default setting the system goes to during calibration and you can thus confirm the system is calibrating as you will see the setting has changed from what you set to 74 degrees during this process.
   
2. Turned off ignition.
   
3. Removed fuse #39 "HVAC Batt" in the engine compartment fuse block. [There are two other fuses (#48 & #55) that are for the HVAC/IGN that do NOT have to be removed.]
   
4. Leave fuse #39 out for at least one minute.
   
5. Re-insert fuse #39.
   
6. Start the vehicle but DO NOT touch any of the AC-Heater controls. The display of temp should now read 74degrees.Let the car run for 2 minutes without touching any controls.
   
7. Turn off the engine for at least 10 seconds but NOT more than 30 seconds and restart the engine. The system should now be re-calibrated.

 

[Denali Deen]

I HAVE ALSO BEEN HAVING ISSUES WITH MY 2010 DENALI. IT KINDA HAS A MIND OF ITS OWN SOMETIMES IT WILL GET COLD QUICK AND STAY THAT WAY OTHER TIMES IT WILL JUST BLOW COOL TO WARM AIR AND NOT TILL I HAVE BEEN DRIVING AND THE ENGINE IS UNDER LOAD WILL IT START TO COOL OFF AND GET TO THE RIGHT TEMP. THEN WHEN COMING TO A STOP IT WILL WARM BACK UP. I HAVE HAD IT PROFESSIONALLY EVAC'D AND RECHARGED AND THAT MADE NO DIFFERENCE. REPLACED THE COMPRESSOR AND NO REAL DIFFERENCE AND THEN REPLACED THE ORIFICE TUBE. THAT WAS FAIRLY CLOGGED IT SEEMS A LITTLE BETTER BUT WILL STILL RANDOMLY CUT OUT AND STOP BLOWING AS COLD AS IT SHOULD. I AM IN THE SOUTH AND 100 DEGREES AND FULL HUMIDITY IS AN EVERYDAY THING SO I REALLY WOULD LIKE TO FIND THE ISSUE TO MINE AS WELL. COULD A BAD/GOING BAD CONTROL HEAD CAUSE THAT?

 

[2010gmcyukon]

Following up on my post, as I had a shop look at the AC and it is now working. Here are their notes:

Initial inspection of HVAC system found pressure line frozen at orifice tube on evaporator side. Hook machine up and found low pressures on high and low side. Recover R134a from vehicle and found .4 lb in vehicle. System calls for 2.5 lb. Evac and recharge required.
​

They also said that they put in some UV dye. The system held vacuum and they did not detect any leaks. Not sure what caused the condition, but I'm glad to have it working again.