ASE Heating & Air Conditioning Flashcards
6 cards from real ASE practice questions. Tap to flip, then mark Knew It or Still Learning — missed cards come back until you master them.
Read the first 6 ASE Heating & Air Conditioning flashcards as text
What is the purpose of the receiver-drier in an A/C system that uses a thermal expansion valve (TXV)?
Answer: Stores liquid refrigerant and absorbs moisture with desiccant
The receiver-drier stores excess liquid refrigerant, filters debris, and uses a desiccant bag to absorb moisture that could damage the system.
When performing an A/C performance test, the technician should check the temperature differential between which two points?
Answer: Center dash vent outlet and ambient air
A properly functioning A/C system should produce air at the center dash vent that is 35–45°F cooler than the measured ambient temperature.
What does a low high-side pressure and a low low-side pressure indicate in an A/C system?
Answer: Refrigerant undercharge
Both pressures being low simultaneously is the classic symptom of an undercharged system due to refrigerant loss from a leak.
Which type of blower motor speed control uses a variable resistance to reduce voltage to the motor at lower speed settings?
Answer: Resistor block
A blower motor resistor block drops voltage by adding resistance in series with the motor, reducing speed at lower fan settings.
What is the MOST common cause of A/C system contamination that requires flushing the entire system?
Answer: Compressor failure that sends metallic debris through the system
A failed compressor can scatter metal particles throughout the A/C system, requiring complete flushing to prevent new component damage.
A vehicle equipped with automatic temperature control (ATC) uses which type of sensor to detect sunlight intensity and adjust output?
Answer: Photovoltaic sunload sensor
A photovoltaic sunload sensor detects solar radiation intensity and signals the ATC module to increase cooling output to maintain cabin comfort.