My 2000 Jeep Grand Cherokee Laredo's electric fan is not kicking on. I tried a jumper wire from the positive side of the battery to the fan harness and it did not kick on, How do I check it with a voltometer?

You want to check it with ohms on your multimeter. connect your meter to the leads and the reading shouldnt really be over 1 ohm. if you dont get a reading then your motor has a short and if it is above 1 ohm it might be burned up. also insure the fan turns freely. if the bearings are siezed up then that could also be the problem regardless of weither the motor was good or not.