1. Wiper Speed and Function:
* Are they wiping effectively? Do they clear the windshield completely, or are there streaks, smearing, or areas they miss? This points to wiper blade issues (worn rubber, misalignment).
* Do all speeds work? If only the fastest speed works, or none at all, it suggests a problem with the motor or its associated wiring/switch.
* Intermittent speed function: If the intermittent setting is erratic (wiping too fast or too slow, or not at all), there's likely a problem with the intermittent wiper motor or its control circuit.
2. Wiper Blades:
* Blade condition: Check the rubber on the blades for cracking, hardening, or significant wear. Replace them if necessary. This is the most common cause of poor wiping.
* Blade attachment: Ensure the blades are securely attached to the wiper arms. Loose blades will not wipe effectively.
* Wiper arm movement: Observe the full arc of the wiper blades. They should move smoothly and cover the entire windshield surface. Binding or sticking could indicate a problem with the arm or linkage.
3. Wiper Motor and Linkage:
* Motor sound: Listen carefully while the wipers are running. Unusual noises (grinding, squealing, clicking) suggest a problem with the motor itself, possibly worn bushings or gears.
* Linkage: Inspect the linkage connecting the motor to the wiper arms for any damage, looseness, or binding. Sometimes a small pebble or debris can cause binding.
* Wiper motor fuse: Check the fuse associated with the wipers in the fuse box (consult your owner's manual for location and amperage). A blown fuse will prevent the wipers from working.
4. Wiper Switch and Wiring:
* Switch operation: Check if the switch itself is functioning correctly. If it feels loose or unresponsive, it may need replacement.
* Wiring: While less likely, damaged or corroded wiring can interrupt the electrical signal to the wiper motor. Inspect the wiring harness for any visible damage, especially around the connections.
5. Windshield Condition:
* Cleanliness: A dirty windshield will make even the best wipers struggle. Clean the windshield thoroughly to rule this out.
* Cracks or chips: A damaged windshield can interfere with wiper blade contact.
If you've checked all of these and the wipers still aren't working correctly, it's time to consult a mechanic. They have the tools and expertise to diagnose more complex issues. Be sure to describe the specific problem you're experiencing as clearly as possible.
