Burning smell

Hello, I’m going to take my truck in to the shop as soon as I can, but I was hoping to just get some insight from people in this forum if you don’t mind. When I start my truck, there’s this burning smell that comes through the vents, but will go away Eventually. One time there was a little bit of smoke, but not since that one time, but it still has the burning smell when I first crank it up. What would create a burning smell that would go away? I’ve looked through the engine, I don’t see any hoses loose or leaks, or anything like that. 2012, four-cylinder 4 x 4 is what my truck is

 

https://www.tacomaworld.com/threads/blower-motor-connector-burnt.817795/

https://www.tacomaworld.com/threads/burnt-up-ac-blower-motor-and-wiring.813152/

https://www.tacomaworld.com/threads/diy-ac-or-heater-only-blowing-on-high-heres-a-fix.541843/

 

the blower motor is so easy to access, it's worth looking under there yourself