ASE ASE Heating & Air Conditioning 3

Question 1

What is the purpose of the receiver-drier in an A/C system that uses a thermal expansion valve (TXV)?

Accepted Answer

Stores liquid refrigerant and absorbs moisture with desiccant

Answer

Cools refrigerant before the evaporator

Answer

Regulates compressor speed

Answer

Measures refrigerant temperature

Question 2

When performing an A/C performance test, the technician should check the temperature differential between which two points?

Accepted Answer

Center dash vent outlet and ambient air

Answer

Compressor inlet and outlet

Answer

Evaporator inlet and condenser outlet

Answer

Heater core inlet and outlet

Question 3

What does a low high-side pressure and a low low-side pressure indicate in an A/C system?

Accepted Answer

Refrigerant undercharge

Answer

Overcharge of refrigerant

Answer

Compressor not pumping

Answer

Restricted expansion valve

Question 4

Which type of blower motor speed control uses a variable resistance to reduce voltage to the motor at lower speed settings?

Accepted Answer

Resistor block

Answer

PWM module

Answer

Relay pack

Answer

Transistor controller

Question 5

What is the MOST common cause of A/C system contamination that requires flushing the entire system?

Accepted Answer

Compressor failure that sends metallic debris through the system

Answer

Overcharge of refrigerant

Answer

Clogged cabin air filter

Answer

TXV valve sticking open

Question 6

A vehicle equipped with automatic temperature control (ATC) uses which type of sensor to detect sunlight intensity and adjust output?

Accepted Answer

Photovoltaic sunload sensor

Answer

Thermistor

Answer

MAP sensor

Answer

Infrared thermocouple