Jeeps that have both fans, may not show signs of overheating unless being operated in extreme conditions. Conditions like pulling heavy loads or being driven hard in mid summer heat; Jeeps that do not have the benefit of the extra cooling fan will show signs of overheating much quicker if the fan motor stops working for any reason. The electric cooling fan is designed to come on when the vehicle reaches operating temperature or when the A/C is turned on. With the AC selected, the computer will command the fan to come on. It’s best to check the two wire harness that is attached to the passenger side of the fan shroud for power and ground. If using a power probe tester, the harness can be unplugged and power and ground supplied to check fan operation. If the fan works but there is no power being supplied normally, it’s a good possibility that the cooling fan control module has stopped working (open circuit).
