C972 is where the connector for the diode is located.
But the diode is physically located in the BJB.
A most likely scenario is that the Heater Control Module is damaged. That is the black plastic part behind the controls on the dash.
If jumping power makes the blower motor spin, you just bypassed that switch. Being it and the blower motor resistor are both in line, both have to be suspect. If it's not the blower resistor it must be the control module.