Prepare for the ASE HVAC certification exam with these practice questions and answers. This guide covers heating systems, air conditioning, refrigeration cycles, electrical components, and diagnostic procedures.
Q: A faulty low pressure switch.
Answer: An air conditioning system with a variable displacement compressor has poor performance in high demand situations. All of these would cause this condition EXCEPT:A. A low refrigerant charge.B. A faulty control valve.C. A faulty low pressure switch.D. A weak compressor.
Q: Technician A
Answer: Technician A says the clutch relay protects the control head from the clutch circuit’s high current. Technician B says open clutch relay windings result in compressor clutch engagement at all times. Who is correct?A. Technician AB. Technician BC. Both A and BD. Neither A nor B
Q: The refrigerant changes from a vapor to a liquid as it receives heat from the cabin air.
Answer: All of these statements are true about an automotive air conditioner’s evaporator EXCEPT:A. It removes humidity from the air.B. Refrigerant flows from the bottom to the top.C. Refrigerant enters the evaporator as a liquid.D. The refrigerant changes from a vapor to a liquid as it receives heat from the cabin air.
Q: Orange with a white stripe.
Answer: The signal wire between the electronic climate control module and the low pressure sensor is:A. Green with a yellow stripe.B. Orange with a white stripe.C. White with an orange stripe.D. Orange with a red stripe.
Q: Technician B
Answer: A blower motor operates only on high speed. Technician A says there could be a short in the motor’s power feed. Technician B says it has a faulty blower motor resistor. Who is correct?A. Technician AB. Technician BC. Both A and BD. Neither A nor B
Q: Technician B
Answer: A compressor clutch oil is being tested. There are 12 volts at the connector, and the ground is good. The coils resistance is 0.00 Ohms. Technician A says the coil has an open in its windings. Technician B says the clutch coil has a short and has failed the resistance test. Who is correct?A. Technician AB. Technician BC. Both A and BD. Neither A nor B
Q: A frozen expansion valve.
Answer: A vehicle’s air conditioner blows cold air while cruising, but warm air when it’s sitting at stop lights. The LEAST likely cause of this condition is:A. An overheating engine.B. A weak electric fan motor.C. A frozen expansion valve.D. Debris in the condenser fins.
Q: Both A and B
Answer: The carpet is wet on the passenger’s side of a vehicle. Technician A says a leaking heater core will cause this condition. Technician B says this is the result of a clogged evaporator case drain tube. Who is correct?A. Technician AB. Technician BC. Both A and BD. Neither A nor B
Q: Both A and B
Answer: An automotive air conditioner has poor performance. The in-cabin temperature sensor may be at fault. Technician A says the in-cabin temperature sensor is an NTC and tested for resistance with an ohmmeter. Technician B says a disconnected aspirator will cause poor A/C performance. Who is correct?A. Technician AB. Technician BC. Both A and BD. Neither A nor B
Q: Technician B
Answer: A (TXV) thermostatic expansion valve system blows cold air for five minutes and then goes warm. Technician A says a low refrigerant charge causes this condition. Technician B says there is moisture in the system. Who is correct?A. Technician AB. Technician BC. Both A and BD. Neither A nor B