William,
Since it won't turn off. Chances are it isn't the resister. Power is supplied by the relay to the switch. From the switch, sent to the resister, and finally to the blower motor. Since it runs at all times, either there is a short to power between the switch and the motor, or the switch is bad and allowing power to the motor at all times.
Do this, just as a simple test. Remove the relay and see if the motor stops. If it does, then the problem is between the relay and the motor. If it continues to run, then we have a short after the switch.
I attached the entire wiring schematic below for the HVAC system. I highlighted a lot of wires related to the blower motor for your reference.
Let me know what I can do to help or if you have other questions.
Take care,
Joe
See pics below. Note: The schematic is for manual control HVAC. If you have automatic climate control, let me know. Also, the schematic was two pages long. I had to cut the pics in half to make them readable for you. I did overlap them so you can follow from one to the next.
Images (Click to make bigger)
Friday, October 22nd, 2021 AT 8:33 PM