HVAC Review

Both high-side and low-side pressures are low with the engine running and the selector set to the air-conditioning position. Technician A says that the system is under charged. Technician B says that the cooling fan could be inoperative. Which technician is correct?

• Technician A only

• Technician B only

• Both technicians A and B

• Neither technicians A nor B

Which component is located in the low pressure side of the refrigeration system?

• Accumulator

• Thermal Expansion Valve (TXV)

• Orifice tube

• Receiver-drier

A lack of cooling is being diagnosed. A technician discovers that the high pressure line is hot to the touch on both sides of the orifice tube. Technician A says that is normal operation for an orifice tube system. Technician B says that the orifice tube may be clogged. Which technician is correct?

• Technician A only

• Technician B only

• Both technicians A and B

• Neither technician A nor B

Frost is observed on the line between the condenser and the receiver-drier. Technician A says that this is normal if the air conditioning were being operated on a hot and humid day. Technician B says that a restriction in the line or at the outlet of the condenser could be the cause. Which technician is correct?

• Technician A only

• Technician B only

• Both technicians A and B

• Neither technician A nor B

The owner of a vehicle equipped with an orifice tube-type air conditioning system complains that the inside of the vehicle does not cool properly. The air conditioning compressor clutch rapidly cycles on and off whenever the air conditioning is on. Technician A says that the system is likely low on refrigerant. Technician B says that the most likely cause is an electrical short in the wiring to the air conditioning compressor clutch. Which technician is correct?

• Technician A only

• Technician B only

• Both technicians A and B

• Neither technician A nor B

A customer states that the vehicle does not cool as well as it should. Technician A says that the system could be low on refrigerant charge. Technician B says that if the electric radiator cooling fan is not functioning, this can cause a lack of cooling inside the vehicle. Which technician is correct?

• Technician A only

• Technician B only

• Both Technicians A and B

• Neither technician A nor B

An automotive air conditioning system is being tested for a lack of cooling complaint. Both high and low side pressures are higher than normal. Technician A says that the system is low on charge. Technician B says that the system is overcharged. Which technician is correct?

• Technician A only

• Technician B only

• Both technicians A and B

• Neither technician A nor B

The high side pressure is higher than normal. Technician A says that the compressor may be defective. Technician B says that the condenser may be clogged with leaves or other debris blocking the airflow. Which technician is correct?

• Technician A only

• Technician B only

• Both Technicians A and B

• Neither Technicians A nor B

A customer complained of a clear liquid leaking from underneath the vehicle on the passenger side after driving for a short time with the air conditioning on. The problem only occurs when the air conditioning is operating. Technician A says that the evaporator may be leaking. Technician B says that this may be normal condensed water formed on the cold evaporator coil. Which technician is correct?

• Technician A only

• Technician B only

• Both Technicians A and B

• Neither Technician A nor B

Both the low and high side pressures are within normal ranges, yet the inside of the vehicle is not cooling. Technician A says that a partially clogged orifice tube could be the cause. Technician B says that too much refrigerant oil in the system could be the cause. Which technician is correct?

• Technician A only

• Technician B only

• Both Technicians A and B

• Neither Technician A nor B