1. Check the obvious: Make sure the wiper blades themselves aren't frozen, damaged, or dislodged. Try gently wiggling the non-working blade.
2. Check the fuses: Consult your car's owner's manual to locate the fuse(s) for the windshield wipers. Inspect them for damage (blown fuse will show a broken filament). Replace any blown fuses with fuses of the same amperage rating.
3. Check the wiper motor: Listen carefully while you turn on the wipers. If you hear a clicking sound, the motor might be failing. This usually requires professional repair or replacement.
4. Check the wiper linkage: Sometimes, the linkage connecting the motor to the wipers can become dislodged or broken. Visually inspect the linkage for any damage or misalignment. This often requires professional repair.
5. Check the wiper fluid: A lack of fluid won't directly cause one wiper to fail, but it could mean there's a clog or a problem with the fluid delivery system that's affecting one side.
If you're uncomfortable doing these checks yourself, take your car to a mechanic. Driving with only one working wiper, especially in rain or snow, is dangerous and could impair your visibility.
