Air conditioning not working correctly?

Please let us know what happens, we are interested to see what it is.

Cheers, Ken

Yes, if you have separate left and right temp controls, you will have 2 actuators. I don;t see any Yukon that has a 5.7 and you don't say if this is ATC or not so my info may not be accurate.
Alldata states the dash has to be removed to access the right side.

I'm just a tech here so I don't know how the site works in that respect. I'm afraid you still don't have the engine size right I assume you are referring to a 5.3L.

As far as removing the dash, that is no simple task and any instructions would be multiple pages long so it's not something we could post here. You might want to look into a service subscription from AlldataDIY. Com. It's the same manuals we use but you only have to purchase one vehicle. That will have everything you ever need to know about your vehicle. I think they run about $25 for a single vehicle for a year.

Hello,

It sounds like the system is down on refrigerant. Here is a guide that will help you get the problem fixed.

https://www.2carpros.com/articles/air-conditioner-how-to-add-freon

and

https://www.2carpros.com/articles/car-air-conditioner-not-working-or-is-weak

Please let us know what happens, we are interested to see what it is.

Cheers, Ken

GMC recomonends unplugging the a/c compressor drilling a 1/4 inch hole in the ac plenum downstream of the fan, run the heat on high recirculat for 10 mins, then spray ing shot bursts spaying the deodorizing aerosol kit. Then continue to run the a/c for an additional 15-20 to dry it. Thenplug the hole with RTV gasket sealer. Then plug in the a/c compressor. Done!

Hi and thanks for using 2carpros.com

Most times when the AC only produces cold air when the car is moving, it is the result of low Freon. What you should do is check the system's low and high side pressures to determine if one or both are low.

Based on outside temperatures, pressures will change. Here are a couple examples of proper pressure based on temperature:

80 degrees F low side should be 45psi to 50psi.
High side should be 175psi to 210psi

Take a look at this link. It discusses how to recharge the system:

https://www.2carpros.com/articles/air-conditioner-how-to-add-freon

Here is another link which discusses issues with the AC not working:

https://www.2carpros.com/articles/car-air-conditioner-not-working-or-is-weak

The proper way to check and diagnose the problem is by using gauges to determine both the low and high side pressures, especially when it stops working. This link shows the gauges in use.

https://www.2carpros.com/articles/re-charge-an-air-conditioner-system

If you find that the low side is too low and the high side it too high, suspect a blockage of the orifice tube or expansion valve. Note: Over charging the system can cause it to malfunction, too. If you do have gauges, let me know what you find and also what the ambient temperature is when checked. That way I can better help.

Let me know if this helps or if you have other questions.

Take care,
Joe

The vents are actuated by vacuum from the engine. My guess is that you are looking for a vacuum leak under the dash or near the fire wall where the supply line come from. With the engine running, listen for a hissing sound.

Which control system do you have the manual or automatic version?
In both the Left (driver) side is the easier one to replace, It is on the bottom of the HVAC case and you only need to remove the console (depending on option) and lower
insulator panel to get to it.
The right (passenger) side on the other hand is a pain. For it the dash has to come out to get to the top of the HVAC case and the actuator.

Then you need to calibrate them.

It could be the actuators or it is possible it is the control head itself. It is possible to test them if you have a dealer level scan tool. I would opt to test them first before tearing the truck apart.