In testing wiper arm force on the windshield, which condition is used to take the measurement?

In testing wiper arm force on the windshield, which condition is used to take the measurement?

• A. In the full outwipe position with the blade attached
• B. In the full outwipe position with the blade removed
• C. In the park position
• D. With the blade folded against the arm

Answer: (B)

To get a true measure of the wiper arm’s force on the windshield, you isolate the arm from the blade’s influence and test at the moment of maximum contact. Measuring in the full outwipe position ensures the arm is pressed against the glass with the greatest load during a wipe, while removing the blade eliminates the blade’s stiffness, curvature, and friction from the reading. The blade itself would add its own resistance and deflection, distorting the force you’re trying to quantify. Parking the wiper or having the blade folded against the arm yields far different, non-representative forces because the arm isn’t applying the same contact pressure, so those conditions wouldn’t give a consistent measure of the arm’s true force against the glass.

To get a true measure of the wiper arm’s force on the windshield, you isolate the arm from the blade’s influence and test at the moment of maximum contact. Measuring in the full outwipe position ensures the arm is pressed against the glass with the greatest load during a wipe, while removing the blade eliminates the blade’s stiffness, curvature, and friction from the reading. The blade itself would add its own resistance and deflection, distorting the force you’re trying to quantify. Parking the wiper or having the blade folded against the arm yields far different, non-representative forces because the arm isn’t applying the same contact pressure, so those conditions wouldn’t give a consistent measure of the arm’s true force against the glass.