Question 1
Technician A says that evacuating an A/C system will remove air and moisture from the
system. Technician B says that evacuating an A/C system will remove dirt particles from
the system. Who is right?
A. Technician A only
B. Technician B only
C. Both A and B
D. Neither A or B
CORRECT ANSWER
The correct answer is A. Evacuating an A/C system removes air and moisture from the
system. The receiver/drier may contain a filter or strainer to catch and trap foreign particles
and dirt, but this remains in the receiver/drier and is not removed during the evacuation
procedure.
Question 2
There is a growling or rumbling noise at the AC compressor when the system is off and the
engine is running. The noise stops when the system is turned on. Technician A says that a
bad compressor bearing could be the cause. Technician B says that a bad compressor
clutch bearing could be the cause. Who is right?
A. Technician A only
B. Technician B only
C. Both A and B
D. Neither A or B
CORRECT ANSWER
The correct answer is B. The compressor clutch bearing allows the rotor/pulley assembly to
spin independently of the compressor shafts when the A/C system is off. When the engine is
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,running and the A/C system is off, the compressor clutch bearing is spinning. When the A/C
system is turned on, the rotor/pulley assembly and the armature are locked together by the
magnetic action of the compressor clutch coil.
Question 3
Recovering/recycling equipment must have shutoff valves located within 12-in (30cm) of
the hoses' service ends so that:
A. oil can be added to the refrigerant
B. the unit can be isolated from the refrigerant source
C. the filter can be changed without disconnecting the hoses
D. refrigerant discharge can be kept to a minimum
CORRECT ANSWER
The correct answer is D. According to the Clean Air Act, recovery/recycling equipment must
have shutoff valves located within 12-in. (30 cm) of the hoses' service ends so that
refrigerant discharge to the atmosphere can be kept to a minimum.
Question 4
When recovering refrigerant from an a/c system, how long should the technician wait after
the recovery/ recycling unit has been turned off to see if there is any residual pressure in
the system?
A. 1 minute
B. 5 minutes
C. 10 minutes
D. 15 minutes
CORRECT ANSWER
The correct answer is B. The technician should wait five minutes and watch the gauge to see
if there is any residual pressure. If there is, repeat the process to remove any remaining
refrigerant until the A/C system holds a stable vacuum for at least five minutes.
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,Question 5
A system with a low pressure on the low side and a heavy frost accumulation on the inlet
side of the Thermostatic Expansion Valve (TXV) indicates a:
A. TXV stuck open
B. clogged condenser
C. defective compressor
D. Clogged screen or the TXV stuck closed
CORRECT ANSWER
The correct answer is D. A low pressure reading in the low side and a heavy frost
accumulation on the inlet side of the TXV indicates a clogged screen at the expansion valve
inlet or a TXV stuck closed.
Question 6
A blower motor only works on high speed. Which of the following causes is the most
LIKELY?
A. defective blower relay
B. defective blower resistor
C. defective blower switch
D. blown fuse or tripped circuit breaker
CORRECT ANSWER
The correct answer is B. Answer D is incorrect because if the blower furs was blown or circuit
breaker tripped, the blower would not work at all. Answer A is incorrect because a blower
relay is generally only used for the high blower speed and this is working. Answer C, the
blower switch is a possible cause but the most likely cause for operation on only high speed
is that a portion of the resistor assembly is burned out.
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, Question 7
A customer complains that when accelerating his car with the A/C on, the cold air flow
from the dash outlets shifts to the floor. Technician A says that this is caused by a faulty
check valve in the vacuum reservoir. Technician B says that this condition is due to a
vacuum leak. Who is right?
A. Technician A only
B. Technician B only
C. Both A and B
D. Neither A or B
CORRECT ANSWER
The correct answer is C. If, during hard acceleration, air routing changes by itself, it's
probably due to a leak in the system or a faulty check valve in the vacuum reservoir. A
complaint that the mode shifts from the dash to the floor at wide-open throttle is evidence
that the system isn't holding vacuum.
Question 8
When pressure testing the cooling system on a late model gasoline engine vehicle, the
pressure on the tester drops but no leaks can be found in the engine compartment.
Technician A starts the engine and, seeing the pressure on the tester gauge increase, says
that there is an internal leak, a blown head gasket. Technician B says that there cannot be
an internal leak because the engine oil looks normal, not milky like it would be if coolant
were present, and there is no white smoke coming from the exhaust pipe. Who is right?
A. Technician A only
B. Technician B only
C. Both A and B
D. Neither A or B
CORRECT ANSWER
The correct answer is A. If the engine is started while pressure testing a cooling system and
the pressure immediately increases, there could be a head gasket leak, but not into the
crankcase. The coolant may be going out the tailpipe, but since this is a late model gasoline
engine vehicle and equipped with a catalytic converter, there is no white smoke from the
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Technician A says that evacuating an A/C system will remove air and moisture from the
system. Technician B says that evacuating an A/C system will remove dirt particles from
the system. Who is right?
A. Technician A only
B. Technician B only
C. Both A and B
D. Neither A or B
CORRECT ANSWER
The correct answer is A. Evacuating an A/C system removes air and moisture from the
system. The receiver/drier may contain a filter or strainer to catch and trap foreign particles
and dirt, but this remains in the receiver/drier and is not removed during the evacuation
procedure.
Question 2
There is a growling or rumbling noise at the AC compressor when the system is off and the
engine is running. The noise stops when the system is turned on. Technician A says that a
bad compressor bearing could be the cause. Technician B says that a bad compressor
clutch bearing could be the cause. Who is right?
A. Technician A only
B. Technician B only
C. Both A and B
D. Neither A or B
CORRECT ANSWER
The correct answer is B. The compressor clutch bearing allows the rotor/pulley assembly to
spin independently of the compressor shafts when the A/C system is off. When the engine is
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,running and the A/C system is off, the compressor clutch bearing is spinning. When the A/C
system is turned on, the rotor/pulley assembly and the armature are locked together by the
magnetic action of the compressor clutch coil.
Question 3
Recovering/recycling equipment must have shutoff valves located within 12-in (30cm) of
the hoses' service ends so that:
A. oil can be added to the refrigerant
B. the unit can be isolated from the refrigerant source
C. the filter can be changed without disconnecting the hoses
D. refrigerant discharge can be kept to a minimum
CORRECT ANSWER
The correct answer is D. According to the Clean Air Act, recovery/recycling equipment must
have shutoff valves located within 12-in. (30 cm) of the hoses' service ends so that
refrigerant discharge to the atmosphere can be kept to a minimum.
Question 4
When recovering refrigerant from an a/c system, how long should the technician wait after
the recovery/ recycling unit has been turned off to see if there is any residual pressure in
the system?
A. 1 minute
B. 5 minutes
C. 10 minutes
D. 15 minutes
CORRECT ANSWER
The correct answer is B. The technician should wait five minutes and watch the gauge to see
if there is any residual pressure. If there is, repeat the process to remove any remaining
refrigerant until the A/C system holds a stable vacuum for at least five minutes.
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,Question 5
A system with a low pressure on the low side and a heavy frost accumulation on the inlet
side of the Thermostatic Expansion Valve (TXV) indicates a:
A. TXV stuck open
B. clogged condenser
C. defective compressor
D. Clogged screen or the TXV stuck closed
CORRECT ANSWER
The correct answer is D. A low pressure reading in the low side and a heavy frost
accumulation on the inlet side of the TXV indicates a clogged screen at the expansion valve
inlet or a TXV stuck closed.
Question 6
A blower motor only works on high speed. Which of the following causes is the most
LIKELY?
A. defective blower relay
B. defective blower resistor
C. defective blower switch
D. blown fuse or tripped circuit breaker
CORRECT ANSWER
The correct answer is B. Answer D is incorrect because if the blower furs was blown or circuit
breaker tripped, the blower would not work at all. Answer A is incorrect because a blower
relay is generally only used for the high blower speed and this is working. Answer C, the
blower switch is a possible cause but the most likely cause for operation on only high speed
is that a portion of the resistor assembly is burned out.
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, Question 7
A customer complains that when accelerating his car with the A/C on, the cold air flow
from the dash outlets shifts to the floor. Technician A says that this is caused by a faulty
check valve in the vacuum reservoir. Technician B says that this condition is due to a
vacuum leak. Who is right?
A. Technician A only
B. Technician B only
C. Both A and B
D. Neither A or B
CORRECT ANSWER
The correct answer is C. If, during hard acceleration, air routing changes by itself, it's
probably due to a leak in the system or a faulty check valve in the vacuum reservoir. A
complaint that the mode shifts from the dash to the floor at wide-open throttle is evidence
that the system isn't holding vacuum.
Question 8
When pressure testing the cooling system on a late model gasoline engine vehicle, the
pressure on the tester drops but no leaks can be found in the engine compartment.
Technician A starts the engine and, seeing the pressure on the tester gauge increase, says
that there is an internal leak, a blown head gasket. Technician B says that there cannot be
an internal leak because the engine oil looks normal, not milky like it would be if coolant
were present, and there is no white smoke coming from the exhaust pipe. Who is right?
A. Technician A only
B. Technician B only
C. Both A and B
D. Neither A or B
CORRECT ANSWER
The correct answer is A. If the engine is started while pressure testing a cooling system and
the pressure immediately increases, there could be a head gasket leak, but not into the
crankcase. The coolant may be going out the tailpipe, but since this is a late model gasoline
engine vehicle and equipped with a catalytic converter, there is no white smoke from the
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