We need to back track to find out what the voltage is at the control processor (resistor). I understand you have voltage but we need to know how much voltage on each wire. Let's start with A. This should be 12 volts at all times. Next B, this should be different depending on what speed you have the fan set on. So let's check it on each setting.
Clearly if the blower motor comes on when you put 12 volts to then I suspect we have a wiring issue where you are not getting 12 volts on the B+ wire. If you don't have 12 volts there then the blower will not operate.
Let us know what the actual voltage is on each of these wires by back probing the connector with it turned on.
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Friday, April 30th, 2021 AT 2:23 PM