Which action is typical for ensuring safe operation of windshield wiper electrical systems?

• A. Relay
• B. Fuse/circuit breaker
• C. Diode
• D. Resistor

Answer: (B)

Overcurrent protection for the windshield wiper circuit is essential to prevent wiring damage and fires. A fuse or circuit breaker serves this purpose by opening the circuit when current exceeds a safe level, stopping excessive heat and protecting the motor, wiring, and connectors. Fuses are sacrificial and must be replaced after they trip, while circuit breakers can be reset after a fault, offering reusable protection.

Relays control power to the wiper motor, letting a low-current switch do the heavy lifting; they don’t limit current or stop faults. Diodes can suppress voltage spikes from back-EMF, helping protect driving electronics, but they aren’t the main safety device for overcurrent protection. Resistors limit current in some circuits, yet they would waste power and alter performance, so they’re not used as the primary protection in a windshield wiper system.