u/Glam_Boozled

2017 Cadillac xt5. Months ago we had a -20° weekend. I didn't go anywhere so my car sat a couple days. When I went to start it, it didn't turn over. I tried to start a second time and it sounded like a 'hard' start. Since then there has been no heat/ac or anything blowing at all through the vents. We changed the HVAC fuse, along with a couple others that seemed relevant to the problem (they weren't technically blown). Tested the battery. Then took to a shop. They replaced the control module, and that didn't fix the problem either.

Fluid levels were all checked and are fine.

Any other tips or insight?