How To Turn On Rear Wiper

Is your rear wiper stubbornly refusing to activate? It's a common frustration for many car owners, especially during inclement weather. A functional rear wiper is crucial for maintaining clear visibility through your rear window, enhancing safety during driving, particularly in rain, snow, or when roads are splashed with grime. Knowing how to properly activate and troubleshoot this feature is essential for every driver. Let's get your rear wiper working again!

Symptoms of a Malfunctioning Rear Wiper

Before diving into the potential causes and solutions, let's confirm that your rear wiper is indeed malfunctioning. You might be experiencing one or more of the following symptoms:

• No Response: The most obvious symptom – the rear wiper doesn't move at all when you activate the switch.
• Intermittent Operation: The wiper might work sporadically, sometimes responding and sometimes not.
• Slow or Jerky Movement: The wiper moves very slowly or in a jerky, uneven manner.
• Wiper Stops Mid-Cycle: The wiper starts moving but stops abruptly before completing its cycle.
• Sprayer Malfunction: The rear window washer fluid doesn't spray when you activate the wiper. This could be a separate issue but is often linked.
• Unusual Noises: Grinding, clicking, or other unusual noises emanating from the rear wiper motor area.

Root Causes of a Rear Wiper Failure

Several factors can contribute to a malfunctioning rear wiper. Identifying the root cause is the first step towards a successful repair. Here's a breakdown of the most common culprits:

• Faulty Wiper Motor: The motor is the heart of the rear wiper system. Over time, it can wear out due to constant use or exposure to the elements. The internal components, such as the windings or brushes, can fail, leading to a complete or intermittent failure.
• Blown Fuse: A blown fuse is often the simplest explanation. The rear wiper circuit is protected by a fuse, and a power surge or short circuit can cause it to blow, cutting off power to the wiper motor.
• Wiring Issues: Damaged or corroded wiring can interrupt the electrical signal to the wiper motor. This can happen due to wear and tear, exposure to moisture, or rodent damage. Common problem areas include the wiring harness that runs from the car's body to the rear hatch or tailgate.
• Faulty Switch or Stalk: The switch or stalk that controls the rear wiper can malfunction. The contacts inside the switch can wear out or become corroded, preventing the signal from reaching the wiper motor.
• Wiper Arm Linkage Problems: The linkage connects the wiper motor to the wiper arm. If this linkage becomes loose, damaged, or seized, it can prevent the wiper arm from moving properly. This is more common in older vehicles.
• Corrosion and Rust: In regions with harsh weather conditions, corrosion and rust can build up on the wiper motor shaft and linkage, hindering its movement.
• Rear Hatch Wiring Harness (Common Failure Point): The wiring harness that passes through the hinge area of the rear hatch is a very common failure point. Constant opening and closing of the hatch can cause wires to break or become damaged. This is often the cause of intermittent rear wiper problems.

What Happens If You Ignore a Malfunctioning Rear Wiper?

Ignoring a malfunctioning rear wiper might seem like a minor issue, but it can have serious consequences:

• Reduced Visibility: The primary function of the rear wiper is to clear your rear window, providing a clear view of what's behind you. Without it, your visibility is significantly reduced, especially in wet or snowy conditions.
• Increased Risk of Accidents: Reduced visibility increases your risk of accidents, as you may not be able to see approaching vehicles or obstacles behind you.
• Potential for Fines: In some jurisdictions, it's illegal to drive with impaired visibility. You could face a fine if your rear wiper isn't functioning properly.
• Further Damage: Neglecting a minor issue can lead to more significant problems down the line. For example, a partially functioning wiper motor might draw excessive current, potentially damaging other electrical components.

Recommended Fixes

Here's a step-by-step guide to diagnosing and fixing a malfunctioning rear wiper:

1. Check the Fuse: This is the easiest and often the first thing to check. Consult your owner's manual to locate the fuse for the rear wiper. Use a fuse tester or visually inspect the fuse to see if it's blown. If it is, replace it with a fuse of the same amperage rating.
2. Inspect the Wiper Blades: While not directly related to the motor function, worn or damaged wiper blades can contribute to poor visibility. Replace them if they are cracked, torn, or leave streaks on the window.
3. Test the Wiper Motor: If the fuse is good, the next step is to test the wiper motor. You'll need a multimeter and some basic wiring knowledge. Disconnect the connector from the wiper motor and use the multimeter to check for voltage when you activate the rear wiper switch. If there's no voltage, the problem lies upstream (switch, wiring, etc.). If there is voltage, the motor itself is likely faulty.
   • DIY Test: You can also try applying power directly to the wiper motor using jumper wires connected to the battery. If the motor runs, the problem is likely in the vehicle's wiring or switch. Be cautious when working with electrical systems.
4. Examine the Wiring: Carefully inspect the wiring harness that connects to the rear wiper motor, paying close attention to the area where the harness passes through the rear hatch or tailgate hinge. Look for signs of damage, corrosion, or broken wires. Repair any damaged wires using electrical tape or butt connectors. Consider replacing the entire harness if the damage is extensive.
5. Inspect the Wiper Switch: If the fuse is good and there's no voltage at the motor, the switch could be the culprit. This usually requires removal of the steering column shroud and access to the switch. Testing the switch requires a multimeter and knowledge of its wiring configuration. A faulty switch should be replaced.
6. Check the Wiper Arm Linkage: Examine the linkage between the wiper motor and the wiper arm. Look for any signs of looseness, damage, or corrosion. Lubricate the linkage with penetrating oil to ensure smooth movement. If the linkage is severely damaged, it may need to be replaced.
7. Clean the Wiper Motor Shaft: If the wiper motor shaft is corroded or rusty, it can impede the movement of the wiper arm. Clean the shaft with a wire brush and apply a lubricant.

Cost Estimates and Shop Advice

The cost of repairing a malfunctioning rear wiper can vary depending on the cause of the problem and whether you choose to DIY or take it to a professional mechanic.

• Fuse Replacement: A fuse typically costs just a few dollars. This is the cheapest and easiest fix.
• Wiper Motor Replacement: Replacing a wiper motor can cost anywhere from $50 to $200 for the part itself, depending on the make and model of your vehicle. Labor costs can range from $50 to $150, depending on the complexity of the job.
• Wiring Repair: The cost of wiring repair can vary depending on the extent of the damage. Simple repairs might cost $30 to $50, while more extensive repairs or harness replacements can cost $100 to $300.
• Switch Replacement: Replacing the wiper switch can cost between $50 and $150 for the part and $50 to $100 for labor.

Shop Advice: If you're not comfortable working on electrical systems or if you suspect a more complex issue, it's best to take your vehicle to a trusted mechanic. A qualified mechanic can diagnose the problem accurately and recommend the appropriate repairs. Always get a written estimate before authorizing any work.

Credibility and Common Issues

Rear wiper failures are a common issue across many makes and models. Some vehicles are known to have specific problems related to their rear wiper systems. For example, certain SUV models are prone to wiring harness failures in the rear hatch due to the constant opening and closing. Checking online forums and vehicle-specific communities can provide valuable insights into common issues and potential solutions for your particular vehicle.

Technical Service Bulletins (TSBs): Automakers often issue TSBs to address known problems with their vehicles. These bulletins provide detailed information on how to diagnose and repair specific issues. Check with your dealer or search online for TSBs related to your vehicle's rear wiper system. Some TSBs may cover repairs under warranty, even if your vehicle is beyond the standard warranty period.

Mileage and Failure: Rear wiper motor failures often occur around the 80,000 to 150,000-mile mark, depending on usage and environmental conditions. Regular maintenance, such as inspecting and lubricating the wiper arm linkage, can help extend the life of your rear wiper system.

By following these steps, you can effectively diagnose and repair a malfunctioning rear wiper, ensuring clear visibility and safe driving in all conditions. If you encounter any challenges or are unsure about any aspect of the repair, don't hesitate to seek professional assistance. Good luck!