Evaporator fan speed erratic

The Model No. Of My Fridge Is Gsh25jfta Bb. Serial No. Hm236617. Is It Possible To Know If The Evaporator Fan Has A Thermistor Or Not. I Would Like To Have Replacement Fan In Hand When I Disassemble And Do The Motor Test Procedure. DO I NEED EVAPORATOR FAN PN AP3191003 WITH OR AP3875639 WITHOUT.