* Stripped wiper arm spindle: This is the most common cause. The small metal shaft on the wiper arm that connects to the motor mechanism has become stripped of its threads or is otherwise damaged, preventing the arm from turning.
* Damaged wiper transmission linkage: Some wiper systems have a linkage connecting the motor to the wiper arms. This linkage could be broken, bent, or otherwise dislodged. This is less common than a stripped spindle.
* Broken or disconnected wiper arm: While less likely if the motor is working, the wiper arm itself could be broken near the connection point.
What to do:
1. Inspect the wiper arm spindle: Carefully examine the spindle on the wiper arm where it connects to the motor mechanism. Look for any obvious damage, stripped threads, or bending. This is usually the easiest place to start.
2. Check the wiper transmission linkage (if applicable): If your car has a visible linkage system, check for any broken or dislodged parts.
3. Try to wiggle the wiper arm: If the spindle is stripped, the wiper arm will likely move freely without resistance.
Solutions:
* Replace the wiper arm: This is the most common and usually easiest solution for a stripped spindle. They are relatively inexpensive and easy to replace. You can find replacement wiper arms at most auto parts stores.
* Repair the wiper transmission linkage (if applicable): If the linkage is broken, you might be able to repair it, but this often requires more mechanical skill and may not be cost-effective. Replacement might be necessary.
* Professional repair: If you're not comfortable working on your car yourself, take it to a mechanic. They can diagnose the problem accurately and perform the necessary repairs.
In short, don't focus on the motor; the issue is in the mechanical connection between the motor and the wiper blade itself.
