yo i had this same problem.. it might be your temp sensor.. if that goes out then your fan wont know when your car is gettin hot and wont come on.. the fan is set on the switch to turn on when the motor gets to a certain temp and turn off after it cools to a certain temp.. i donno just a suggestion cuz i had this same problem but I replaced the temp sensor and whallaaa it went away.. anyways g/l