2014 CTS HVAC problems after battery changed....
 

Our 2014 CTS AWD Premium was working fine, but still had the original 7 year old battery. This started causing problems last month (cold weather), so I priced a new Delco battery. When I saw I'd have to remove some of the interior trunk carpeting in order to change it myself, I paid the Cadillac dealer $75 to change it. I have a two post lift in my garage (in another state!), so I'm familiar with mechanical things, rebuilding engines, etc. But from what I saw online, you can cause the OnStar battery to go dead if you don't replace the main battery absolutely correctly. All things considered, I decided to pay the dealer to change it. Been driving for 51 years, and always changed my own batteries. So I get the car back, and all of a sudden the dash vents blow no air, hot or cold!! A/C works great, as does the heater. Fan works great, too, as it will blow hot or cold air out the defroster, or at foot level from the heater ducts, or out of both top and bottom. But not the dash vents!!! All was well until I took the car in to have the battery changed. It's a little too coincidental for me! I think something went wrong at the dealer, and they're not going to fess up. Any thoughts from you guys? Anyone else ever had this happen before? Thank you very much. If I wasn't almost 70 years old, I would've tried changing it myself. I paid good money to avoid the very problems I'm now having!!!!

TTT......Anyone, help? Someone has surely had this problem, and what procedures remedied the situation........

If you replaced it, then you may have missed something, I advise you to contact the service. I had the same issue about 2 years ago. So, my battery died and I went to our local service to change it and I ended up changing it. Everything seemed fine for 2 weeks, but after that my car started to turn on and off randomly which scared me. I went back to the service and wanted some answers, but I got none. I went back home and started to search on the internet about car batteries and ran into an amazing website https://batterytools.net/ that had all sorts of information about car batteries and how they operate. After I’ve read a lot about the topic I decided to fix the battery myself and I surprisingly succeeded.