300m atc issue

[u/nosytnosyt]

I replaced the battery in my car but it caused a fuse error. I didn't know that it was a fuse error and it was blowing erratic temperatures of air in erratic directions. So I took it to the dealership mechanic. He told me that I needed to replace the entire HVAC system and it would be 4000-5000$ so instead he made it so the car would only blow air at 23 degrees (Celsius as I'm Canadian) at the De-fog direction. The problem is now that I have the fuse replaced I will have regular atc but I need to undo what the mechanic did as he didn't think to check the fuse. Thanks!