Constant Blinking Snowflake

[SirGeorgio]

Hello, i decided to join the forum and become apart of the family. But i ask for the wizards to come forward and help me with a dilemma I'm in before i pull my hair out! My AC runs cold for a while but decides randomly to disengage the compressor then it blows hot air. I have seen it disengage and engage constantly but again its random... The snowflake button then starts to blink. It will blink constantly until the car starts to move then its lukewarm at best then it randomly decides when it wants to work again... I seen forum posts and videos that it can blink 3 times and then it turns off the snowflake button but in my case I'm not that lucky. It just blinks turns off for a second and back at it again. I changed basically almost all sensors at this point and I'm stumped. It holds pressure and there no leaks of any kind. Has anyone experienced this or am i that unlucky individual? Forgive the lengthy post i just want to be as descriptive as possible for anyone with knowledge. Thank you for reading!

 

[kchotrodtrk]

welcome to TYF.

you said you changed basically all the sensors...? which ones?

im an 01-06 guy and behind their grills there are two sensors one on the driver side that is for the mirror and one on the pass side that only communicates w the BCM concerning the ac. my 02 would randomly blink three times and then shut down the compressor until it randomly came back on, sometimes days later, sometimes in just a few minutes. i changed the pass side ambient temp sensor and its fixed. you should research this for your year vehicle!

i am only commenting because i know how frustrating it can be and i just fixed it about two weeks ago so im still celebrating the win.

get over to the intro thread n let everyone know you are here and list your specs

 

[OR VietVet]

Welcome to the forum from Oregon. Post pics of your rig please.

First: You say no leaks. How did you arrive at that and have you put a set of gauges on the system to monitor the readings when the problem occurs? What sensor(s) did you replace and what brand? Sounds to me like it is low but without readings and the ambient temp at the time of the readings, I just don't know. The problem could be the controller. This part:

https://www.rockauto.com/en/moreinfo.php?pk=1553954&cc=1433255&jsn=1001

I am just guessing at the controller application because you failed to supply any info about your rig. I can assure you that not every 2007 to 2014 rig is exactly the same. C'mon man!



We recommend that you put all your rig(s) info in your signature so we all don’t have to guess at year, make, model, engine size, trans, rear axle locker…….etc. While you may have posted pertinent info in your first post, you may forget to do it again and the info is needed by us anyway. Makes it way easier on all members that attempt to help, to have that info right up front. It is also recommended that you take a pic of your RPO codes, on the inside cover of the glove box, and post that image in your signature. All this info will greatly help those that will try to help with a problem.


If there is any other info, like upgrades, mods or recent mechanical/maintenance work done, that would be helpful in any post as well. Too many times a question is asked by the poster and after about 10 responses we find out that the poster has done recent work to attempt to fix the problem or work that was done that SEEMS not related to the problem.

 

[SirGeorgio]

Yes, excuse me for that! My rig is a 2008 Tahoe RWD 5.3 Vortec! Its an LT so it does have dual climate zones. I had it in the shop and at this point even im puzzled we changed the Low Pressure Ac Pressure switch, and ambient sensors! He pressured tested it and used UV light and checked every corner of the car regarding the ac system! So we came to the conclusion it could be the actual headunit? Maybe i dont know yet! But i have a different ac head unit that were gonna test this coming week and test run that!

 

[SirGeorgio]

No mods have been done to the engine as of yet. i stay on top of everything with the vehicle! Only cosmetic mods have been done so far. Also thank you for the explanation VietVet!!! All parts have been OEM. It just decides on its own when it starts doing it...

 

[OR VietVet]

If the system has been opened within the last 6-12 months and was not vacuumed down correctly or long enough you could have moisture in the system that is freezing up and shutting down.


Could you look at the RPO codes on the inside of the glove box and list any codes that start with a C or a D. That controller application asks for gobs of these options. Some even having to do with heated outside mirrors.

 

[OR VietVet]

No mods have been done to the engine as of yet. i stay on top of everything with the vehicle! Only cosmetic mods have been done so far. Also thank you for the explanation VietVet!!! All parts have been OEM. It just decides on its own when it starts doing it...

Go to the top right of home page and click on your screen name and put all the rig info in your signature. It will be on every post you make from here out and you don't have to remember to type it all in. Mine is highlighted in blue on my post.

 

[SirGeorgio]

These are the RPO Codes the vehicle has. I did use AC Pro thinking it was just low but it never did anything or changed!

 

[OR VietVet]

Does your controller look like this: https://www.rockauto.com/en/moreinfo.php?pk=1490572&cc=1441040&jsn=946

Or like the other one I posted in my first response?

 

[SirGeorgio]

My controller is this digital one. At the moment its working the way it should. Arctic air atm.