I have a 1998 cherokee sport and I have a question about the cooling fan. Every time I turn on the heat or the ac the cooling fan will come on about every 10-15 seconds and will run for about 2-4 seconds until I turn it off and it does'nt matter if the engine is warm or cold. I am planning on changing the thermostat and having the cooling system flushed when I get a couple of bucks. Other than that the temp gauge reads that all is good and both the ac and heat are working well so my question is, is this normal?? Why does it always come on and for only a very short time?This is my first XJ and I'm still learning so please bear with me. Its the I6 auto. Thanks for any tips and advice.

 

Your aux fan will come on when you turn the ac on or defroster,in some cars it also comes on when the heat is on,but I do not think jeep had that. The reason it is coming on with the defrost or heater is the ac pump is also coming on,it removes moisture from the inside and incoming air to keep the moisture level down inside the car.