AC final
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: - ANSWER✅✅✅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? - ANSWER✅✅✅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? - ANSWER✅✅✅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? - ANSWER✅✅✅Both A and B
A refrigerant identifier will do all of the following except: - ANSWER✅✅✅Display the percentage of
water vapor (H2O)
A refrigerant retrofit label must contain all of the following except - ANSWER✅✅✅The amount of R-
12 removed from the system
A slipping compressor clutch may be due to all of the following, except: - ANSWER✅✅✅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? -
ANSWER✅✅✅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
,AC final
375 psig. What is the most likely cause of this condition? - ANSWER✅✅✅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? - ANSWER✅✅✅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? - ANSWER✅✅✅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? -
ANSWER✅✅✅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? - ANSWER✅✅✅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: - ANSWER✅✅✅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? - ANSWER✅✅✅Neither A nor B
All of the follow are true about engine thermostats EXCEPT: - ANSWER✅✅✅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 -
ANSWER✅✅✅Infrared Temperature Sensor
, AC final
All of the following alternate refrigerants are approved for automotive use, except -
ANSWER✅✅✅Duracool 12a
All of the following are removed from an air-¬conditioning system during evacuation, except: -
ANSWER✅✅✅Lubricant
All of the following conditions could cause poor passenger compartment heating system performance
EXCEPT - ANSWER✅✅✅Thermostat stuck in the closed position.
All of the following may need to be performed as part of a retrofit procedure from R-12 to R-134a
refrigerant, except - ANSWER✅✅✅Replace all air conditioning system hoses with ¬barrier hoses
All of the following statements about a typical air-¬conditioning system set to MAX cooling are true,
except: - ANSWER✅✅✅The heater coolant flow control valve is open
All of the following statements about system evacuation are true, except: - ANSWER✅✅✅If vacuum
does not reach 24 to 26 in. Hg (20.3 to 23.5 kPa absolute), evacuate for a longer time
All of the following statements about the air conditioning circuit are true, EXCEPT: -
ANSWER✅✅✅Heat transfer is accomplished by two pressure and two temperature systems
All of the following statements about variable displacement compressors are true, except: -
ANSWER✅✅✅Variable displacement compressors have a cycling clutch.
All of the following statements are true, except: - ANSWER✅✅✅A refrigerant identifier will identify
R-134a at any purity.
An air-conditioning compressor clutch failed due to overheating. What is the most likely cause of the
failure? - ANSWER✅✅✅High resistance in the compressor
An engine coolant temperature switch or sensor is used to directly or indirectly energize the: -
ANSWER✅✅✅radiator fan motor relay.
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: - ANSWER✅✅✅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? - ANSWER✅✅✅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? - ANSWER✅✅✅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? - ANSWER✅✅✅Both A and B
A refrigerant identifier will do all of the following except: - ANSWER✅✅✅Display the percentage of
water vapor (H2O)
A refrigerant retrofit label must contain all of the following except - ANSWER✅✅✅The amount of R-
12 removed from the system
A slipping compressor clutch may be due to all of the following, except: - ANSWER✅✅✅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? -
ANSWER✅✅✅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
,AC final
375 psig. What is the most likely cause of this condition? - ANSWER✅✅✅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? - ANSWER✅✅✅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? - ANSWER✅✅✅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? -
ANSWER✅✅✅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? - ANSWER✅✅✅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: - ANSWER✅✅✅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? - ANSWER✅✅✅Neither A nor B
All of the follow are true about engine thermostats EXCEPT: - ANSWER✅✅✅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 -
ANSWER✅✅✅Infrared Temperature Sensor
, AC final
All of the following alternate refrigerants are approved for automotive use, except -
ANSWER✅✅✅Duracool 12a
All of the following are removed from an air-¬conditioning system during evacuation, except: -
ANSWER✅✅✅Lubricant
All of the following conditions could cause poor passenger compartment heating system performance
EXCEPT - ANSWER✅✅✅Thermostat stuck in the closed position.
All of the following may need to be performed as part of a retrofit procedure from R-12 to R-134a
refrigerant, except - ANSWER✅✅✅Replace all air conditioning system hoses with ¬barrier hoses
All of the following statements about a typical air-¬conditioning system set to MAX cooling are true,
except: - ANSWER✅✅✅The heater coolant flow control valve is open
All of the following statements about system evacuation are true, except: - ANSWER✅✅✅If vacuum
does not reach 24 to 26 in. Hg (20.3 to 23.5 kPa absolute), evacuate for a longer time
All of the following statements about the air conditioning circuit are true, EXCEPT: -
ANSWER✅✅✅Heat transfer is accomplished by two pressure and two temperature systems
All of the following statements about variable displacement compressors are true, except: -
ANSWER✅✅✅Variable displacement compressors have a cycling clutch.
All of the following statements are true, except: - ANSWER✅✅✅A refrigerant identifier will identify
R-134a at any purity.
An air-conditioning compressor clutch failed due to overheating. What is the most likely cause of the
failure? - ANSWER✅✅✅High resistance in the compressor
An engine coolant temperature switch or sensor is used to directly or indirectly energize the: -
ANSWER✅✅✅radiator fan motor relay.
