I did this morning! I got in, started it up, turned the defrost on, smelled burning. It's cold, couldn't tell if it was the blazer or a wood stove right away. Then there was smoke. It's nothing big, but will require minor attention. I noticed when I replaced the blower resistor that there was (and is) some insulation in the box. I did pull some out when I did the resistor, but I guess I have to pull the box open. Obviously, at one point there was something living there, dunno if they moved out, but they will.

 

lol. that seems to be common. that resister gets red hod so if there was anything touching it it will cook it. bought a truck that was sitting in a field for a few years and there was a ton of stuff in there