Recreational Vehicle (RV) Technician Practice Test

If a water pump runs continuously while the control relay is de-energized, what is the most likely cause?

1. The pump is faulty

2. The switch remains closed

3. The power supply is faulty

4. The relay is not working correctly

The correct answer is: The switch remains closed

The most likely cause of a water pump running continuously while the control relay is de-energized is that the switch remains closed. When the switch that controls the power to the pump is not functioning properly and remains closed, it allows power to flow to the pump even when the relay is supposed to be inactive. This scenario indicates that the designed mechanism to control the pump's operation is not performing as intended. The switch's closed position essentially bypasses the relay's control, leading to continuous operation of the pump despite signals to the contrary. Other options, such as a faulty pump, a faulty power supply, or issues with the relay itself, would normally lead to different types of failure, such as the pump not running at all, intermittent operation, or problems related to power delivery. In this case, the specific condition of continuous operation despite the relay being de-energized highlights the failure of the switch to open and break the electrical connection.