1. Multi-Function Switch (Wiper Switch): This is the most likely culprit. The switch controls both wipers, and a failing internal component can cause one wiper to stop working while the other continues. This switch is usually located on the steering column. Replacement is the most common solution.
2. Wiper Motor: While less likely if only one wiper is affected, a failing wiper motor *could* be causing the problem. A partially malfunctioning motor might only have enough power to operate one wiper arm. This is less probable since both arms usually receive power from the same motor via linkage. A bad connection to the motor is also a possibility.
3. Wiring and Connections: Check the wiring harness from the multi-function switch to the wiper motor. Look for broken wires, corroded connectors, or loose connections. Pay close attention to the area where the harness splits to supply power to both wiper arms. A visual inspection for damage and a careful probing with a multimeter are necessary.
4. Wiper Linkage: Less likely, but damage or a problem within the wiper linkage itself (the mechanical arms and joints that move the wipers) could prevent one wiper from operating correctly even if the motor is working. Inspect the linkage for broken or binding parts.
5. Fuse: While less likely to cause just one wiper to fail, a partially blown fuse (check the owner's manual for the wiper fuse location) could be weakening the circuit, causing insufficient power for the right wiper.
Troubleshooting Steps:
1. Check the Fuses: This is the easiest first step. Locate the wiper fuse and visually inspect it for a blown element.
2. Inspect the Wiring: Carefully examine the wiring harness from the switch to the motor, looking for any obvious damage or corrosion. Pay particular attention to where the harness splits to the left and right wiper motors.
3. Test the Wiper Motor (Advanced): This requires some electrical knowledge and a multimeter. You'll need to disconnect the motor and test its continuity and power supply. If you're uncomfortable with this step, it's best to take it to a mechanic.
4. Replace the Multi-Function Switch: This is usually the most effective solution if the above steps don't reveal a problem. This is usually an inexpensive part, but replacing it may require some mechanical skill, and a consultation with a mechanic for advice may be useful beforehand.
Recommendation:
Start with the fuse check and wiring inspection. If these are fine, the most probable cause is a faulty multi-function switch. Replacing this is the most likely solution and is generally a cost-effective repair compared to investigating the motor or linkage. If you're not comfortable working on your car's electrical system, it's always best to take it to a qualified mechanic.
