If you replaced the controller, then we have to have a wiring issue. Here is where I want to start: The fan speed is controlled by what is called the blower motor resistor. I want you to remove it and inspect it to see if there is evidence of overheating or damage.
If you look below, I attached the directions for removal and replacement. Let me know if you are comfortable performing the procedure.
I'm questioning if there is a short at that point causing other issues. The other indicators you mentioned aren't directly related to the blower motor, so this is the easiest thing to check first.
Let me know what you find.
Take care,
Joe
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Friday, March 18th, 2022 AT 8:19 PM