Heating, Ventilation, and Air Conditioning (HVAC ) Electrical Practice Test

What troubleshooting step should be taken if the blower motor is not running?

1. Inspect the thermostat settings

2. Check for a blown fuse in L2

3. Examine the blower relay

4. All of the above

The correct answer is: All of the above

In the scenario where the blower motor is not running, it is essential to consider multiple troubleshooting steps to pinpoint the issue effectively. Inspecting the thermostat settings is crucial because the thermostat controls the operation of the blower motor. If the settings are incorrect or if the thermostat is malfunctioning, it may not signal the blower motor to operate, leading to the system being completely inactive. Checking for a blown fuse in L2 is also a vital step because blown fuses can interrupt power to the blower motor. The HVAC system relies on fuses to protect against electrical surges or faults; if a fuse is blown, the circuit will be disconnected, preventing the blower motor from functioning. Examining the blower relay is necessary as well, since the relay serves as a switch that activates the blower motor when the system calls for heating or cooling. A faulty relay may fail to close the circuit, thus preventing the blower motor from receiving the necessary power to operate. Taking all of these steps into account provides a comprehensive approach to troubleshooting the blower motor issue. Therefore, utilizing a combination of these methods ensures that various potential problems are addressed and increases the likelihood of identifying the root cause effectively.