2012 jeep grand cherokee cooling fan not working

The cooling fan in a Jeep Grand Cherokee keeps engine temperatures at the correct level by kicking on during times when the engine reaches higher-than-average temperatures. Without it, the engine can reach dangerous temperatures and damage engine components. If the cooling fan stops working, most do-it-yourself mechanics can troubleshoot it in a few minutes and decide what component needs replaced.

Step 1

Open the driver's side door. Pull the cover from the fuse box on the end of the panel. Using the fuse diagram on the inside of the cover, locate the fuse for the cooling fan and remove it with needle-nose pliers. If the metal link inside the fuse is broken, replace the fuse. If the fuse link it not broken, re-install the fuse and cover.

Step 2

Remove the cover for the power distribution block in the engine compartment, toward the firewall on the driver's side. Using the diagram on the inside of the distribution cover, locate the 40 Amp fuse. Pull the fuse with needle-nose pliers. If the metal link inside the fuse is broken, replace the fuse. If the fuse link is not broken, re-install the fuse and cover.

Step 3

Unplug the electrical connector running to the fan motor, which is in the middle on the rear of the fan shroud.

Step 4

Attach a fused jumper wire to the terminal on the cooling fan that is more exposed after unplugging the electrical connector. Connect the other end of the jumper wire to the positive battery terminal. Attach another jumper wire to the other terminal, connecting it to the negative battery terminal. If the fan does not operate, continue troubleshooting.

Step 5

Switch the wires to the opposite terminals. If the fan still does not operate, the cooling fan motor and assembly must be replaced. If the fan does operate, the vehicle must be taken into a professional service center for testing on the PCM, which controls the cooling fan relays.

References

• "Haynes Repair Manual: Jeep Grand Cherokee 1993 thru 2004"; John H. Haynes and Larry Warren; 2005

Things You'll Need

• Needle-nose pliers
• Fused jumper wire
• Jumper wire

Writer Bio

Eric Grosso has been a journalist since 2002, working as a staff reporter covering government events, school districts, sporting events and entertainment acts. He has been published in "The Vindicator" and "The Jambar" as well as websites including KFFL and Plugged In Online. Grosso holds a Bachelor of Arts in telecommunications and journalism from Youngstown State University.

Your Jeep Grand Cherokee‘s radiator fan has one of the most important jobs on the vehicle.  It is the last line of defense between you and an overheating engine.  If the radiator fan is not working, it’s a serious problem.

Just because the radiator fan is not on does not mean that it is not working.  They are designed to only run when needed.  If your Grand Cherokee is running hot, and the fan is not running we’ve laid out the most common causes of this issue below.

Jeep Grand Cherokee Radiator Fan Not Working Causes

There are a few simple reasons that the fan would not be cycling on.  Although the fan itself can go bad, that’s definitely not the place to start a diagnosis.

Here are the most common reasons that your radiator fan does not turn on:

Before poking your hands around your fan, make sure to treat it like it still could come on, and and keep your hands out of its path.

Wiring

The first thing that you would want to do is locate the fuse for your Grand Cherokee’s radiator fan and make sure that it hasn’t blown.  If it is blown, replacing the fuse will only solve the problem for a very limited period of time.  Unless the wiring issue is fixed, the fuse will blow again.

The wiring harness itself can go bad.  Your author has personally had a shredded tire completely pull the fan wiring out of his vehicle.  It can happen.  The fan wiring is some of the more vulnerable wiring in your Grand Cherokee.

You can test the voltage going from the fan relay to the fan itself.  If it is getting 12+ volts, the fan should be coming on.  But if it’s not, which means the fan has gone bad.

This video from Ratchets and Wrenches is a phenomenal resource on how to properly diagnose a wiring problem.

Engine Temp Sensor

Your engine temperature sensor is responsible for relaying your engine temp to the ECU.  Once the temp gets so hot, the ECU commands the radiator fan to come on. If your Grand Cherokee has a bad engine temp sensor the radiator fan won’t know to come on, because the ECU won’t know how hot the engine is.

You’ll need to locate and test the engine temp sensor.  Depending on the model year and engine, the location varies.  If it does end up being this sensor, they are very affordable.

Low Coolant

If the engine coolant level isn’t high enough to keep pressure in the engine it will run hot.  But, there won’t be enough coolant to reach the temperature sensor.  Without the coolant hitting the sensor, the temp reading will be significantly lower than the actual engine temp.  Your Grand Cherokee’s radiator fan will not kick on.

If you do have low coolant, don’t fill it up until the engine has cooled off.  Adding coolant to a radiator dry enough not to trigger the engine temp sensor can cause problems from drastic temperature change.  Let it cool down first.

Fan Clutch

Like any other clutch, a fan clutch will wear out over time.  If everything else seems on the up and up, the springs in the fan clutch have worn past the point of proper function and can no longer do their job.

Conclusion

There are many reasons why your Jeep Grand Cherokee’s radiator fan is not working.  Of all the ones listed above, start with the coolant level, then check the fuse.  After that, the order isn’t so important.  But, you don’t want to miss the easy fixes before you start testing wiring.  

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