- Stripped threads on the wiper arm: If the threads on the wiper arm are stripped, it will not be able to hold the nut securely, causing the arm to flop around. To check for stripped threads, try to tighten the nut by hand. If the nut turns freely without tightening, the threads are likely stripped.
- Loose nut: The nut that holds the wiper arm in place may have come loose over time, causing the arm to become loose. To check for a loose nut, try to tighten it by hand. If the nut tightens easily, it was probably loose.
- Broken or damaged wiper arm: The wiper arm itself may be broken or damaged, causing it to flop around. Look for any cracks or damage on the arm, particularly near the base.
- Problem with the wiper motor or linkage: A problem with the wiper motor or linkage could also cause the wiper arm to flop around. If the wiper motor is not working properly, the arm will not be able to move correctly. If the linkage is damaged or disconnected, it will also cause the wiper arm to become floppy.
If you are not comfortable inspecting or repairing your car's windshield wipers, you should take it to a qualified mechanic for assistance.
