This is most likely the CCRM however, we can test this. Check out the wiring diagram. We need to measure voltage on the low speed fan control circuit coming from the PCM. However this is called a low side driver so we need to see if it is supplying ground by putting the red lead of the meter on battery positive and then the black lead on this wire. If the meter says 12 volts then it is supplying the ground to close the relay and command the fan on.
Take a look at this info and we can go from there.
Images (Click to enlarge)
Wednesday, July 29th, 2020 AT 6:40 PM