My Jeep Grand Cherokee Laredo 2001 4.0lt. motor. started having some problems two days ago. The fan stopped kicking in and I tougth it was the fan relay again since i have replaced before. But i got another one and the fan still wont kick in ...the funny thing is that it will run with the key off ..whenever I turn the car off the fan will kick in and stay on. I tried to find a short somewhere but cant seem to find anything. I would like to know what else could be causing this aside from the relay since i have 4 diferents and they all do the same thing so i am pretty sure is not the relay this time. Could anyone point me in the right direction. Could a bad Powertrain Module be a problem. or should i look somewhere else.

Well, the PCM tells the relay when to turn the fan on but my guess is the relay is wired wrong, shorted etc.
Test the continuity of the fan/relay circuit.

Note: If you have replaced three relays on a 2001 I would check the currant draw of the fan.

Well.. cant seem to find a short but will look harder. Is there any place in particular to look closer? I also checked current draw of the fan as the last post recommended and it was around .50 amp ...is that ok? I will be willing to try anything you would suggest and any tips on how to find a short in such a tangled wiring.

Well.. cant seem to find a short but will look harder. Is there any place in particular to look closer? I also checked current draw of the fan as the last post recommended and it was around .50 amp ...is that ok? I will be willing to try anything you would suggest and any tips on how to find a short in such a tangled wiring.
Then the fan relay has failed and you will need to replace it.

i agree when my relay went bad that's what it did was run the fan with everything off till it killed the battery. i had to pull the plug until i replaced the relay