A relay has gone bad.
Jeep Cherokee's have 2 cooling system fans and one climate control fan. One cooling system fan is fan belt driven and the other one is electric and is turned on/off by the engine computer at about 215*. The A/C and heater fan is electric.
Check your local junk yards.
For the radiator electric fan... Depends which fan you're talking about ? The heater fan or the radiator fan ?
If its the fan speed your talking about its likely that the speed controller on the fan is broken and had its days
The wiring connector is melted. Check wjjeeps.com for pictures and a solution.
The coolant fan continues to run after the engine has cooled and then turned off. The fan continues to run and runs the battery down.
To change the fuse for a heater fan, first, ensure the power to the heater is turned off to avoid electrical shock. Locate the fuse box, and identify the specific fuse associated with the heater fan, which is usually labeled. Remove the blown fuse by pulling it out gently, then replace it with a new fuse of the same amperage. Finally, restore power and test the heater fan to ensure it operates correctly.
Check your cooling fan
Under the hood, on the passenger side firewall, close to the passenger side fender.
To change the heater fan on a 1996 Jeep Grand Cherokee, first disconnect the negative battery cable to ensure safety. Remove the passenger side lower dash panel to access the blower motor. Disconnect the electrical connector and unbolt the blower motor from its housing. Replace it with a new fan, reconnect the wiring, and reassemble the dash panel before reconnecting the battery.
you may have leaves in the fan
When there are loose parts in the fan that runs the heater system, there will be many instances of noise and vibration. A technician should dismantle the system and fix it.