Now when they went to 8plug went to a IRCM module mounted on passenger side inner fender. Something like this.
http://jr.rustecat.com/articles/ircm/assem.html
AC, radiator fan, and fuel pump in it. Now the ect tells this module what temp to turn it on for fan. Also AC should turn module on. AC will not work correctly without radiator fan. You could run codes of it see if code for ect comes up. If so check into that. More than likely the IRCM has gone bad. Please wire direct to fan motor [without module direct power] and make sure it is good before putting in new IRCM. A bad motor pulls too many amps and maybe what destroyed the 1st one and sure don't want to do that to the new module. Wiring diagram for the 92 so you see how it is wired. Module wiring diagram on page2.
http://www.rothfam.com/svo/reference/92-93Mustang.pdf