Q: windshield wiper missing spots

If the missing spots are within the area that is actually swept by the moving wiper blades, that means the spring tension on the arm is inadequate. Sometimes the spring that provides the tension will get rusty and sometimes the arm will bind, too, due to corrosion. If, on the other hand, the wiper arms are just not moving to the full extent over the glass, an adjustment is needed to the left and right stops on the motor or the control. Either fault can be readily repaired. If you desire that this problem be diagnosed by a certified Mechanic, dispatched by YourMechanic right to your location, please request a windshield wiper diagnostic and the responding certified mechanic will get this resolved for you. If you have further questions or concerns, do not hesitate to re-contact YourMechanic as we are always here to help you.