AC final Questions With Complete Solutions
A customer complains of the passenger compartment
temperature always being too hot, cold, or not changing as the
temperature range is changed on the control panel. On an
electronic mode door actuator (motor) system all of the
following could cause this problem, except: Correct Answers
Faulty actuator
A leaking evaporator is being replaced. Technician A says the
new o-rings should be coated with clean refrigerant oil.
Technician B says the some refrigerant oil should be added to
the system prior to recharging the system. Who is correct?
Correct Answers Both A and B
A manifold and gauge set is attached to an operating air
conditioner. The low-side gauge reading is too high and the
high-side reading is too low. What could be the problem?
Correct Answers defective compressor
A rattling noise is heard when the engine is running and the air
conditioning is off. Technician A says this noise may be caused
by too narrow gap between the compressor's armature and rotor.
Technician B says a quick accurate test is to see if the clutch is
the source is to switch on the air conditioning to see if the noise
stops. Who is correct? Correct Answers Both A and B
A refrigerant identifier will do all of the following except:
Correct Answers Display the percentage of water vapor (H2O)
,A refrigerant retrofit label must contain all of the following
except Correct Answers The amount of R-12 removed from
the system
A slipping compressor clutch may be due to all of the following,
except: Correct Answers Low refrigerant charge
A technician finds an air-conditioning clutch will not engage.
Upon initial testing the compressor is receiving both proper
power and ground at the compressor clutch electrical connector;
in addition the compressor input shaft turns freely by hand.
Which of the following is the most likely cause? Correct
Answers Compressor clutch air gap too large
A technician is checking refrigerant system pressures. Both
high- and low-side service ports are located on the A/C
compressor. When the compressor is engaged, the high-side
pressure instantly goes over 375 psig. What is the most likely
cause of this condition? Correct Answers A restricted
discharge hose.
A vehicle is brought into the shop with a complaint of weak
airflow from all the dash vents. Which of the following is the
most likely cause? Correct Answers A dirty cabin air filter
A vehicle returns to the shop for a repeat failure of the
compressor system due to compressor clutch slippage and
overheating. Which of the following is the most likely cause?
Correct Answers High resistance in the compressor clutch
electrical circuit
, A vehicle's automatic temperature control system does not hold
the temperature set on the temperature -control assembly. What
operation should the technician perform first? Correct Answers
Refer to the appropriate diagnostic fault chart
After a vehicle has been driven for 10-15 miles, the heater still
continues to blow cool air. Which of the following is the most
likely cause? Correct Answers Partially blocked heater core
After retrofitting a vehicles air conditioning system from R-12
to R-134a a retrofit label should be affixed under the hood
containing the following information, except: Correct Answers
Technicians name and address
After stabilizing the air-conditioning system, the engine speed is
returned to normal.
Technician A says this is to reduce airflow across the condenser.
Technician B says this is to increase the cooling capacity of the
evaporator.
Who is correct? Correct Answers Neither A nor B
All of the follow are true about engine thermostats EXCEPT:
Correct Answers A thermostat should be removed from a
system if it is running hot
All of the following air-conditioning system sensors are varying
resistive sensors except Correct Answers Infrared Temperature
Sensor
All of the following alternate refrigerants are approved for
automotive use, except Correct Answers Duracool 12a
A customer complains of the passenger compartment
temperature always being too hot, cold, or not changing as the
temperature range is changed on the control panel. On an
electronic mode door actuator (motor) system all of the
following could cause this problem, except: Correct Answers
Faulty actuator
A leaking evaporator is being replaced. Technician A says the
new o-rings should be coated with clean refrigerant oil.
Technician B says the some refrigerant oil should be added to
the system prior to recharging the system. Who is correct?
Correct Answers Both A and B
A manifold and gauge set is attached to an operating air
conditioner. The low-side gauge reading is too high and the
high-side reading is too low. What could be the problem?
Correct Answers defective compressor
A rattling noise is heard when the engine is running and the air
conditioning is off. Technician A says this noise may be caused
by too narrow gap between the compressor's armature and rotor.
Technician B says a quick accurate test is to see if the clutch is
the source is to switch on the air conditioning to see if the noise
stops. Who is correct? Correct Answers Both A and B
A refrigerant identifier will do all of the following except:
Correct Answers Display the percentage of water vapor (H2O)
,A refrigerant retrofit label must contain all of the following
except Correct Answers The amount of R-12 removed from
the system
A slipping compressor clutch may be due to all of the following,
except: Correct Answers Low refrigerant charge
A technician finds an air-conditioning clutch will not engage.
Upon initial testing the compressor is receiving both proper
power and ground at the compressor clutch electrical connector;
in addition the compressor input shaft turns freely by hand.
Which of the following is the most likely cause? Correct
Answers Compressor clutch air gap too large
A technician is checking refrigerant system pressures. Both
high- and low-side service ports are located on the A/C
compressor. When the compressor is engaged, the high-side
pressure instantly goes over 375 psig. What is the most likely
cause of this condition? Correct Answers A restricted
discharge hose.
A vehicle is brought into the shop with a complaint of weak
airflow from all the dash vents. Which of the following is the
most likely cause? Correct Answers A dirty cabin air filter
A vehicle returns to the shop for a repeat failure of the
compressor system due to compressor clutch slippage and
overheating. Which of the following is the most likely cause?
Correct Answers High resistance in the compressor clutch
electrical circuit
, A vehicle's automatic temperature control system does not hold
the temperature set on the temperature -control assembly. What
operation should the technician perform first? Correct Answers
Refer to the appropriate diagnostic fault chart
After a vehicle has been driven for 10-15 miles, the heater still
continues to blow cool air. Which of the following is the most
likely cause? Correct Answers Partially blocked heater core
After retrofitting a vehicles air conditioning system from R-12
to R-134a a retrofit label should be affixed under the hood
containing the following information, except: Correct Answers
Technicians name and address
After stabilizing the air-conditioning system, the engine speed is
returned to normal.
Technician A says this is to reduce airflow across the condenser.
Technician B says this is to increase the cooling capacity of the
evaporator.
Who is correct? Correct Answers Neither A nor B
All of the follow are true about engine thermostats EXCEPT:
Correct Answers A thermostat should be removed from a
system if it is running hot
All of the following air-conditioning system sensors are varying
resistive sensors except Correct Answers Infrared Temperature
Sensor
All of the following alternate refrigerants are approved for
automotive use, except Correct Answers Duracool 12a
