1. The Obvious:
* Fuse: Check the fuse box (usually under the hood or in the dash) for a blown fuse related to the rear wiper. Your owner's manual will show you which fuse is responsible.
* Wiper Switch: Make sure the switch itself is working correctly. Try turning it on and off several times. A faulty switch is a common culprit.
* Washer Fluid: Ensure you have sufficient washer fluid. Some systems won't activate the wiper if the fluid reservoir is low (though this usually triggers a warning light).
2. Mechanical Issues:
* Wiper Motor: The motor itself could be faulty. This often manifests as no noise at all when you try to activate the wiper. You might need to access the motor (located under the rear hatch) to test it directly with a multimeter (if you have experience with this).
* Wiper Linkage: The linkage connecting the motor to the wiper arm can become disconnected, broken, or seized. Inspect this visually for any obvious problems. Rust and corrosion are common culprits in older vehicles.
* Wiper Arm: The wiper arm itself could be loose or broken. Check if it's securely attached.
* Wiper Blade: A severely worn or damaged wiper blade could hinder movement, though it's unlikely to completely prevent operation. Try replacing it with a new one.
3. Electrical Issues (Beyond the Fuse):
* Wiring: Worn, frayed, or corroded wiring between the switch, motor, and fuse can interrupt the electrical circuit. Inspect the wiring harness for any damage, paying close attention to areas that experience movement or are exposed to the elements.
* Ground Connection: A poor ground connection can prevent the motor from receiving power. Trace the ground wire from the motor to its connection point and clean it thoroughly.
4. Intermittent Issues:
If the wiper works sometimes but not others, the problem is likely intermittent and may require more in-depth diagnosis:
* Connector issues: Check all the electrical connectors related to the rear wiper system for corrosion or loose connections. Clean and reseat them.
* Switch malfunction: As mentioned above, a partially functioning switch can cause intermittent problems.
* Motor issues: A failing motor might work sporadically before failing completely.
Troubleshooting Steps:
1. Start with the simplest checks (fuse, switch, fluid).
2. Visually inspect the linkage, arm, and wiring for damage.
3. If you have a multimeter, test the motor and wiring for continuity and power.
4. If you lack experience with electrical work, consider taking your Jeep to a mechanic.
Remember safety first. Disconnect the battery negative terminal before working on any electrical components. If you are unsure about any of these steps, it's best to consult a qualified mechanic.
