Fan not running


#1

I have a 99 jeep grand cherokee. My radiator fan stopped running now my car is overheating. It is an electronic fan. I keep hearing something about the thermostat, bad thermostat could cause the fan not operating?


#2

Not the engine theremostat. There is a thermal swith(thermostat) that screws into the radiator. When it gets hot, it switches the fan on. Look for a sensor screwed in to the radiator with 2 or 3 wires coming out of it. I think it will probably have 2. But if you bridge the wires the fan should run 100% of the time.


#3

replace your tempature sending sensor usealy located on thermostat housing and when your already there replace the thermostat .sometimes if you unplug the sensor while the vehicle is running it will kick the fan on then you will know its the tempature sending sensor.


#4

Thank you I will try those things. I will let you know what happened.


#5

A quick look at a schematic shows this vehicle’s fan is operated by a relay that is controlled by the Powertrain Control Module.

Check the main cooling fan fuse 9 and fuse 5, the latter which should have power with the key in the ON position.

If the main fuse is blown, then (with the engine off) prod the fan blade and make sure the fan motor is not seized up. A seized or dragging motor will blow the No. 9 fuse.

logged off yet again by this worthless new board.