2014 ATS A/C Problems
 

Over a year ago the A/C was not blowing cold and a quick disconnect of the battery solved the problem for a few months. The problem came back and I did the battery thing once again with success but after a while A/C not cold again. I found that I could turn system off and on or change the airflow and the air will blow cold, without touching the battery. Now this situation is keeping us comfortable in the front seat, but now the air is not coming out of the vents at full power. The fan sounds like it should on high but air flow is more like 1/2, so kid in back seat complains. I changed the cabin filter but it did not seem to help much. Any answers will be appreciated. thanks, rrw

All I can figure from your description is you've had some intermittent faults that were disabling the air conditioning, possibly in the HVAC control module - and when you were disconnecting the battery you were clearing the codes, allowing things to start back up for a while. Just my best guess there. Now it sounds like you are having other HVAC issues, and still some strangeness to the Air Conditioning? I think what you need to look for are any DTCs from the HVAC control module, or related modules. This is a complex system, and can't make any reasonable guesses without knowing what is stored.

I will try the battery disconnect again to see if it affects the air flow. I'm not sure how to look for DTCs. We took a 100 mile round trip today in 95 degree heat and were comfortable although wife was not trusting of my decision to take the Caddy.

To see the DTCs (codes) in the HVAC module you would need a code reader or scan tool that can access all system modules. The cheap OBDII code readers can only see engine codes. I have an article put together about that if you are interested. One might be a good investment if you are looking to keep the Cadillac for a while and work on it yourself.

https://www.dtcassist.com/choosing-a-code-reader