It sounds like you have a direct short. You indicated the purchase of a new wiring harness. Is it an OEM part or aftermarket? Did everything match up with what you had? Is it possible for you to take pics so I can see what is happening and indicates which wires started smoking? Or if it was the module smoking, let me know.
I attached a pic below of the wiring schematic of the HVAC blower motor system. When you say module, are you referring to what in the picture is also called the blower motor control switch?
Let me know.
Image (Click to make bigger)
Saturday, December 26th, 2020 AT 10:10 AM