This could be a couple of different problems. It could be that the blower motor control module has gone bad, or there could be a problem with Ground #207 which is located on the right hand side under the dashboard. In the diagrams down below I have included the wiring diagram of the blower motor circuit as well as a diagram of the location of Ground #207. Please inspect this ground and ensure that it is clean, tight, corrosion free, and making good metal to metal contact. Please report back to us with what you find out, and we can go from there, if needed.
Images (Click to enlarge)
Wednesday, January 29th, 2020 AT 3:27 PM