Which protective device is used in some wiper systems to protect the motor from overloads?

• A. A fuse
• B. An internal automatic resetting circuit breaker
• C. A relay
• D. A diode

Answer: (B)

Overload protection for a windshield wiper motor is provided by an internal automatic resetting circuit breaker. When the motor draws more current than it should—such as during a stall or mechanical binding—the breaker trips to open the circuit, preventing damage to the motor and wiring. Once the motor cools and the fault clears, the breaker resets itself and the wipers can resume operation. This type of device is ideal for wiper systems because it provides protective action without needing replacement after an overload.

A fuse, in contrast, would cut power permanently until the fuse is replaced, which isn’t as convenient for intermittent faults. A relay is simply an electrically operated switch used to control the circuit, not to protect the motor from overload. A diode is used for polarity protection or to suppress voltage spikes, not for overload protection of the motor.