How to Troubleshoot the Jeep Grand Cherokee's Cooling Fanby Eric Grosso
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.
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.
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.
Unplug the electrical connector running to the fan motor, which is in the middle on the rear of the fan shroud.
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.
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.