02 Yukon Denali Ac issue.

[Hammer02]

So my ac was recharged recently due to it not blowing cold air. That helped but not much. So I need a little help.

So here are a few things that may help figure this out.

First off the rear ac is cooler than the front.
The wife and I noticed one day the ac got colder as I turned a corner a little fast and sharp. Weird right?
The compressor still go on and off as normal.
No leaks.

I need to know some things I can check before I spend way too much money on parts I dont need. Thanks in advance.

 

[live2pull]

check the condenser for clogged fins

 

[Danny3737]

I’d check the fan clutch as well. Mine started to fail right before I hit 100K

 

[SnowDrifter]

Rear ac colder

Change in temp when turning a corner


My first thought would be the blend door

 

[Hammer02]

Thanks for the ideas...I'll check these things on my next day off and I'll get back with you guys with the results. More ideas are welcome.

 

[Chris2144]

Being the rear is colder?? How cold is colder. If it blows as cold as it should then I would suggest the front has either a clogged orfice tube or a bad blend door actuator. Verify blend door is working correctly. I would say the compressor is likely good since its strong enough to keep the rear ac cold as it's the furthest away. Bad fan clutch would effect both. Check your line going into the fire wall it should be getting cold if it is I would suspect blend door if not then I would suspect the orfice tube is to blame.

 

[Hammer02]

Being the rear is colder?? How cold is colder. If it blows as cold as it should then I would suggest the front has either a clogged orfice tube or a bad blend door actuator. Verify blend door is working correctly. I would say the compressor is likely good since its strong enough to keep the rear ac cold as it's the furthest away. Bad fan clutch would effect both. Check your line going into the fire wall it should be getting cold if it is I would suspect blend door if not then I would suspect the orfice tube is to blame.

It's not as cold as it should be...but just a little bit cooler than the front.

 

[Chris2144]

If both systems are being affected then it could be fan clutch clogged condenser fins I would check the operation of the blend door in the front and then move on from there. Put a gauge on it and see what the pressure is of you have one.

 

[Zeke]

So my ac was recharged recently due to it not blowing cold air. That helped but not much. So I need a little help.

So here are a few things that may help figure this out.

First off the rear ac is cooler than the front.
The wife and I noticed one day the ac got colder as I turned a corner a little fast and sharp. Weird right?
The compressor still go on and off as normal.
No leaks.

I need to know some things I can check before I spend way too much money on parts I dont need. Thanks in advance.

My

So my ac was recharged recently due to it not blowing cold air. That helped but not much. So I need a little help.

So here are a few things that may help figure this out.

First off the rear ac is cooler than the front.
The wife and I noticed one day the ac got colder as I turned a corner a little fast and sharp. Weird right?
The compressor still go on and off as normal.
No leaks.

I need to know some things I can check before I spend way too much money on parts I dont need. Thanks in advance.

My 03 Denali acted the same way last week. It ended up being the ac belt tensioner. Don’t ask me why the rear was colder than the front, but it was. Good luck

 

[latvius]

This is the clue that tells you exactly what it is.
"The wife and I noticed one day the ac got colder as I turned a corner a little fast and sharp. Weird right?"

Not weird, what happened is your blend door swung back to the correct spot with the inertia. Used to happen to my Tahoe. Most likely your blend door (plastic) is broken (split), happened to my rear blend door as well come to think of it. It will work fine and not depending on how the split door spine catches with the other part and may or may not move it.

Your choices are to rip the dash apart in order to separate the plenum (I think that is right name) to replace the door with another plastic one. Or you can use a heater treater mod which will install an aluminum single door that is controlled by the bottom module. Google heater treater .com

The good - it is fairly easy to install, eliminates the top blend module which is hard to get too and replacement door is made of metal so will last a long time.

The bad - you eliminate the dual zone ac to one zone (my wife forgets this and adjusts her side - placebo effect) also you will have to cut open the plenum and create an access door. So the drivers side actually controls the temp for both driver and passenger.

 

[Hammer02]

So little update on the blend door actuator. I got a brand new one and plugged it in before installing it and when I turned the temp knob...it did nothing.

Side note I turned the blend door by hand to see if the air gets cooler...it didnt.

 

[Hammer02]

This is the clue that tells you exactly what it is.
"The wife and I noticed one day the ac got colder as I turned a corner a little fast and sharp. Weird right?"

Not weird, what happened is your blend door swung back to the correct spot with the inertia. Used to happen to my Tahoe. Most likely your blend door (plastic) is broken (split), happened to my rear blend door as well come to think of it. It will work fine and not depending on how the split door spine catches with the other part and may or may not move it.

Your choices are to rip the dash apart in order to separate the plenum (I think that is right name) to replace the door with another plastic one. Or you can use a heater treater mod which will install an aluminum single door that is controlled by the bottom module. Google heater treater .com

The good - it is fairly easy to install, eliminates the top blend module which is hard to get too and replacement door is made of metal so will last a long time.

The bad - you eliminate the dual zone ac to one zone (my wife forgets this and adjusts her side - placebo effect) also you will have to cut open the plenum and create an access door. So the drivers side actually controls the temp for both driver and passenger.

What blend door should I bee looking at? The one I checked it the lower main. But from what I understand there is more.

Also it's not dual zone...if that matters.

 

[latvius]

The blend door right behind the center console. Not sure if the single zone has the actuator at the bottom of the plenum or the top. My guess would be the bottom
BTW You have 3 blend doors, one for the defrost direction, one for the fresh air and one for the temp of hot / cold.

This video is showing how to replace the blend door actuator (hot /cold), not sure if this is a single zone or not but gets you in the right location.

But to be clear the actuator is not the problem it's the blend door that the actuator moves is broken. You can't see it unless you open the plenum which would be a lot of work. Hence the heater treater mod that you cut the access panel into the plenum.

 

[Hammer02]

So I watched the heater treater video for the yukon and Im convinced that blend door isnt broke.With the acuator off I can turn the blend door and get really hot air to come out and back to get cool(not cold)air.So it seems the door is intact.

 

[latvius]

hmmm weird, wonder why the temp changed on a hard turn? Is that actuator completely wrecked? Can you move it by hand? (Should'nt be able too).

 

[Chris2144]

Well from what you have said it seems your blend door is working since it gets hot when you turn it one way and then gets cool the other. So what I know from past experiences is if your compressor is failing generally there rear will be the first to experience problems then the front. Being that the front is worse I wouldn't suspect that but not rule it out just yet either. Plug the actuator in and adjust the temp to verify it's working you say you have already done it by hand and verified the temp does change. Check your fan clutch to make sure it is working and check the condenser fins to make sure there not clogged and it can cool properly. If no problems there then I would put a set of gauges on to get a better idea of what's going on. If the orfice tube for the front is partially clogged then it would cause this problem. For the rear if it is not blowing as cold as it should then that could point to the expansion valve being clogged. Most of the time this is caused by either metal particles from a failing compressor or gel substance from nasty freon.

 

[Hammer02]

So I've been so busy with the AC being fixed and a new problem that I forgot to give an update.

So...it was a leak. A leak that the last place I went to who "Tested for leaks" and then "filled" the coolant..said wasn't there.

New place caught the leak and repaired it and filled me up with the right amount of coolant.Cold as can be! My wife is an ac queen and I've never heard her say she's too cold...and now she does!


Thanks for the help guys!

 

[latvius]

Did they say where the leak was?

 

[Hammer02]

Sorry for the blurry pic...I quickly found it on google.