1. Rear Wiper and Washer:
* Check the fuse: Start by checking the fuse box (likely under the hood and/or inside the dash) for a blown fuse related to the rear wiper and washer. Consult your owner's manual for the correct fuse locations.
* Inspect the wiper motor: Access the rear wiper motor (usually located under the rear cargo area). Check for any obvious damage, loose connections, or corrosion. Try gently wiggling the connector to see if it's loose.
* Examine the wiper arm and linkage: Ensure the wiper arm moves freely and that the linkage isn't broken or seized.
* Test the washer pump: Locate the washer pump (usually near the washer fluid reservoir). You might hear it hum if it's working but isn't pumping fluid. Check for clogs in the washer lines. If it's not working, the pump itself might be faulty.
* Wiring harness: Inspect the wiring harness leading to the motor and washer pump for any damage, breaks, or corrosion. This is often a culprit in older vehicles.
2. Defrost:
* Check the fuse: Again, check the fuse box for a blown fuse related to the rear defrost. Your owner's manual will show you where this fuse is.
* Inspect the rear window defroster grid: Examine the grid lines on the rear window for any broken or damaged elements. A crack or break in the grid will prevent proper defrosting. This is often harder to spot than it sounds. Look closely at each line.
* Power to the grid: Use a multimeter to check for power at the connectors of the rear defrost grid. You'll need to know which wires are positive and negative for your model. If no power is present, the problem lies upstream in the wiring or relay.
* Relay: The rear defrost might use a relay. Locate the relay (consult your owner's manual) and either swap it with a known good relay of the same type or test it with a multimeter.
3. Spare Tire Brake Light:
* Bulb: The simplest check is the bulb itself. Access the spare tire and check the bulb. It's likely a single incandescent bulb. Replace it if it's burned out.
* Wiring: Inspect the wiring running from the light to the vehicle's electrical system. Check for corrosion, breaks, or loose connections.
* Ground: Ensure the light has a good ground connection. A poor ground can prevent the light from working.
* Switch: The spare tire brake light is usually triggered by the brake switch. If the brake lights don't work anywhere else, the problem is likely in the switch.
* Tail light circuit: If the problem's only with the spare tire brake light and not the other lights, it may be part of the tail light wiring circuit, so thoroughly examine that wiring.
General Troubleshooting Tips:
* Owner's Manual: Your Jeep's owner's manual is your best friend. It contains fuse box diagrams, wiring diagrams (sometimes), and troubleshooting tips.
* Wiring Diagrams: If you're comfortable with electrical work, a wiring diagram specific to your year and model Jeep Wrangler will be extremely helpful. You can often find these online through Jeep forums or repair manuals.
* Multimeter: A multimeter is essential for checking voltage and continuity in electrical circuits.
* Jeep Forums: Online forums dedicated to Jeep Wranglers are invaluable resources. Search for similar issues; others have likely encountered and solved the same problems.
Remember to disconnect the negative battery terminal before working on any electrical components to avoid short circuits. If you're not comfortable working with automotive electrical systems, it's best to consult a qualified mechanic. These problems could involve complex wiring and troubleshooting beyond a simple DIY fix.
