2001 Saturn SL2 cooling fan

So I take it ur fan turns on when u turn on the a/c?If ur temp gauge reads normal but ur car over heats then I would say u need a new coolant temp sensor. It's screwed into ur head below where ur upper hose goes on. Make sure u check the connector going to it also they get corroded if it is corroded u will have to clean or replace it. Make sure u get a brass tip coolant sensor the plastic tip ones crack. Also since ur car has been boiling over I would replace the cap it's probably bad as well. Let me know how it goes and what u find.