KMT, I did not run that test but if I am not mistaken when you turn on the defroster the rad fan should run.
UPDATE:
Just tested IRCM for power, and all power feeds to the IRCM are hot!
UPDATE:
Fan ran with ECT disconnected!
Fan does not run when AC or defroster is turned on.
I did what you said and the fan ran when key was turned on!
"if the A/C system is low on refrigerant", that would prevent the fan from running???