Question 1

Technician A says in most cases, problems with the heating system are problems with the engine's cooling system. Technician B says a restricted heater return hose can cause excess heat in the passenger compartment. Who is correct?

Accepted Answer

A)   A only
B)   B only
C)   both A and B
D)   neither A nor B A

Question 2

What are barrier hoses?

Accepted Answer

Barrier hoses have an additional layer of rubber that serves as a barrier to prevent refrigerant from escaping through the pores of the hose. Barrier hoses are required on systems that use R-134a refrigerant.

Question 3

Why does condensed water drip from the air-conditioning system?

Accepted Answer

The evaporator cools (removes heat from) the incoming air and moisture in the air condenses and is allowed to drop from the vehicle in the form of water.

Question 4

Technician A says refrigerant leaves the compressor as a high-pressure liquid. Technician B says the condenser changes the high-pressure liquid refrigerant into a high-pressure vapor. Who is correct?

Accepted Answer

A)   A only
B)   B only
C)   both A and B
D)   neither A nor B

Question 5

The blower motor does not run in any fan switch position. A check with a DMM reveals that power is getting to the motor. Technician A says the motor ground is bad. Technician B says the motor is burned out. Who is correct?

Accepted Answer

A)   A only
B)   B only
C)   both A and B
D)   neither A nor B

Question 6

Heater control valves are operated by a ______.

Accepted Answer

A)   cable
B)   thermostat
C)   vacuum motor
D)   all answers are correct

Question 7

Aluminum tubing is often used to connect air-conditioning components where flexibility is not required.

Accepted Answer

A) True 
 B)False

Question 8

Technician A says an A/C system using CO2 [carbon dioxide] for a refrigerant will not contribute to global warming and is environmentally friendly. Technician B says CO2 refrigerant does not need to be recovered and recycled. Who is correct?

Accepted Answer

A)   A only
B)   B only
C)   both A and B
D)   neither A nor B

Question 9

What tool would you use to check the operation of a vacuum motor?

Accepted Answer

The answer of What tool would you use to check...

Question 10

Which of the following oils can be used in an R-134a system?

Accepted Answer

A)   mineral oil
B)   matural oil
C)   castor oil
D)   PAG oil

Question 11

Technician A says the normal operating pressures of R-134a are slightly lower than the pressures of R-12. Technician B says R-134a boils at 134 degrees Fahrenheit. Who is correct?

Accepted Answer

A)   A only
B)   B only
C)   both A and B
D)   neither A nor B

Question 12

Which of the following statements is NOT correct?

Accepted Answer

A)   The evaporator changes heated refrigerant to a liquid
B)   Automatic temperature controls maintain a set passenger compartment temperature
C)   Air-conditioning/heater systems can be computer controlled
D)   Heaters and air conditioners use the same plenum chambers

Question 13

The heater core is part of the engine's ____________________ system.

Accepted Answer

The answer of The heater core is part of the...

Question 14

The ____________________ displacement compressor automatically changes volume and the amount of refrigerant flow.

Accepted Answer

The answer of The ____________________ displacement compressor automatically changes volume...

Question 15

A heating system includes all the following parts EXCEPT:

Accepted Answer

A)   heater core
B)   ventilation system
C)   receiver/dryer
D)   distribution plenum

Question 16

The evaporator is located _____.

Accepted Answer

A)   in front of the radiator
B)   between the right front inner fender and the firewall
C)   below the condenser
D)   under the dash

Question 17

When the ____________________ door is closed, outside air is blocked from entering the ventilation system while air from the interior of the vehicle is drawn into the heater blower.

Accepted Answer

The answer of When the ____________________ door is closed, outside...

Question 18

A subcooler is located ______.

Accepted Answer

A)   inside the receiver/drier
B)   between the evaporator and accumulator
C)   at the bottom of the condenser
D)   aft of the torpedo room

Question 19

The largest and coolest line/hose in the A/C system is the ______ line.

Accepted Answer

A)   liquid
B)   discharge
C)   suction
D)   equalizer

Question 20

What is an automatic temperature control [ATC] system?

Accepted Answer

The answer of What is an automatic temperature control [ATC]...

Exam 54: Heating and Air Conditioning

Technician A says in most cases, problems with the heating system are problems with the engine's cooling system. Technician B says a restricted heater return hose can cause excess heat in the passenger compartment. Who is correct?

What are barrier hoses?

Why does condensed water drip from the air-conditioning system?

Technician A says refrigerant leaves the compressor as a high-pressure liquid. Technician B says the condenser changes the high-pressure liquid refrigerant into a high-pressure vapor. Who is correct?

The blower motor does not run in any fan switch position. A check with a DMM reveals that power is getting to the motor. Technician A says the motor ground is bad. Technician B says the motor is burned out. Who is correct?

Heater control valves are operated by a ______.

Aluminum tubing is often used to connect air-conditioning components where flexibility is not required.

Technician A says an A/C system using CO₂ [carbon dioxide] for a refrigerant will not contribute to global warming and is environmentally friendly. Technician B says CO₂ refrigerant does not need to be recovered and recycled. Who is correct?

What tool would you use to check the operation of a vacuum motor?

Which of the following oils can be used in an R-134a system?

Technician A says the normal operating pressures of R-134a are slightly lower than the pressures of R-12. Technician B says R-134a boils at 134 degrees Fahrenheit. Who is correct?

Which of the following statements is NOT correct?

The heater core is part of the engine's ____________________ system.

The ____________________ displacement compressor automatically changes volume and the amount of refrigerant flow.

A heating system includes all the following parts EXCEPT:

The evaporator is located _____.

When the ____________________ door is closed, outside air is blocked from entering the ventilation system while air from the interior of the vehicle is drawn into the heater blower.

A subcooler is located ______.

The largest and coolest line/hose in the A/C system is the ______ line.

What is an automatic temperature control [ATC] system?