Started my new truck this afternoon to thaw after a snow and ice storm. Turned up defrost to maximum heat and fan on high setting. Got nothing so tried again half a dozen times thinking I'm doing something wrong but to no avail. Then observed electrical smoke coming from all of the vents and from underneath the dashboard. It got so bad that I had open all 4 doors to let the smoke out and seriously considered a fire extinguisher thinking my brand new truck is going to burn down in my front yard. I was eventually able to open the hood to see if there was a problem in the engine compartment thankfully everything appeared normal. I am an electrician by trade and this was definitely the beginning of an electrical fire.

Update from Jan 19, 2024: Dealership says that a bearing inside the blower motor had seized which caused the blower motor to burn up and consequently fill the cabin with toxic electrical smoke