IF YOU HAVE A RADIATOR ELECTRIC FAN AND IT FAILS THE FAN MOTOR MAY HAVE BURNED BECAUSE IT IS BEING COMANDED BY THE ECM / COMPUTER TO STAY ON HIGH SPEED. WHY WOULD THE ECM ASK THE FAN TO STAY ON HIGH SPEED EVEN THOUGH THE ENGINE IS NOT OVERHEATING AND THE AC IS OF? THERE'S A THING CALLED TFT (TRANSMISSION TEMP SENSOR) AND AT 210 DEGREES THE ECM TRIGGER THE RADIATOR FAN MODULE TO TURN THE FAN ON HIGH SPEED TO TRY AND COOL THE TRANS/COOLER WHICH ON THE 06 GRAND MARQ./ C/V IS BUILT INTO THE LOWER SECTION OF THE A/C CONDENCER. THE ECM STRATEGY CALLS FOR A TEMP. DROP FROM 210 TO 190 BEFORE THE FAN TURNS OFF. BUT WHAT CAN PREVENT THIS COOLING IF THE FAN IS ON YOU ASK , AS I DID. THE ANSWER IS THAT FORD IN IT WISDOM DECIDED TO PLACE A NON SERVICEABLE THERMOSTAT IN THE COOLER ASSEMBLY WHICH IS ONCE AGAIN ALSO KNOWN AS THE A/C CONDENCER. IT SEEMS THAT THE FLUID WAS BYPASSING THE COOLER FINS AND SENT BACK TO THE TRANS NO COOLER THAN IT LEFT THUS THE ECM KEPT CALLING FOR A CONSTANT FAN ON CONDITION WHICH IN TIME CAUSED THE RADIATOR FAN TO BURN OUT. AFTER EVACUATING THE A/C SYSTEM AND REPLACING THE A/C CONDENCER/TRANNY COOLER ASSEMBLY ALL SYSTEMS FUNCTIONED NORMALLY. I WONDER WHAT TRANSMISSION REPAIR SHOPS ARE IN FOR BECAUSE THE COOLER ASSEMBLY CAN'T BE FLUSHED OR SERVICE IN ANY WAY. I GUESS THERE GOING TO HAVE TO GO INTO THE A/C BIZZ. I HOPE THIS HELPS OUT SOMEONE OUT THERE BECAUSE I CERTENTLY HAD MY FUSTRATIONS WITH IT...........