Prepare for the ASE A7 Heating and Air Conditioning certification exam with these practice questions and answers. This guide covers refrigerant handling, AC system diagnosis, heating systems, and automatic climate control.
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