ASE A7 - Heating & Air Conditioning Questions

What is a non-condensable gas? a. Air b. R-12 c. Ozone d. R-134a

a. Air

When replacing a compressor clutch, what is the critical measurement? a. Air gap b. Current (ampere) draw c. Voltage drop d. High-pressure pressure

a. Air gap

Where in the air-conditioning system is the refrigerant a high-pressure liquid a. Condenser outlet b. Evaporator outlet c. Evaporator inlet d. Condenser inlet

a. Condenser outlet

Clear water is observed dripping out from beneath the evaporator. Technician A says that is normal. Technician B says that the evaporator housing is defective and should be replaced. Which technician is correct? a. Technician A only b. Technician B only c. Both Technicians A and B d. Neither Technician A nor B

a. Technician A only

Two technicians are discussing replacing heater hoses. Technician A says that the replacement hoses should be the same length as the original hoses. Technician B says that the replacement hoses should be cut short as possible to allow more coolant flow through the heater core faster. Which technician is correct? a. Technician A only b. Technician B only c. Both Technicians A and B d. Neither Technician A nor B

a. Technician A only

A clogged orifice tube can cause a lack of cooling. a. True b. False

a. True

Which part must be used when refitting a vehicle from R-12 to R-134a refrigerant? a. A new (larger) condenser b. A new service fitting and a retrofit label c. A high-pressure cut-off switch d. Both a and b

b. A new service fitting and a retrofit label

What components in the air-conditioning system may be different on a hybrid electric vehicle? a. Evaporator b. Compressor c. Condenser d. Blower motor

b. Compressor

The blower motor resistors are used to limit ________ to the motor. a. Voltage b. Current c. Airflow d. Both a and b

b. Current

The material used to absorb moisture from inside the conditioning system is called: a. Drier b. Desiccant c. Ester d. PAG

b. Desiccant

A front-wheel-drive vehicle has a broken condenser line. What other vehicle component may also be defective that could have caused the condenser line to break? a. Shock absorber b. Engine mounts c. Cooling fan d. Air-conditioning compressor drive belt

b. Engine mounts

Where in the air-conditioning system is the refrigerant a low-pressure gas? a. Condenser outlet b. Evaporator outlet c. Evaporator inlet d. Condenser inlet

b. Evaporator outlet

When the defrost setting is selected, the air-conditioning compressor operates. a. True b. False

b. False

What must the technician do before checking an air-conditioning system for refrigerant leaks using a black light? a. Evacuate the system b. Install dye in the system c. Overcharge the system by 10 oz d. Turn the system off and allow the pressure to equalize

b. Install dye in the system

The compressor operates continuously with which type of system controls? a. Orifice tube b. POA/EPR

b. POA/EPR

A customer complains that the heater works sometimes, but sometimes only cold air comes out while driving. Technician A says that the water pump is defective. Technician B says that the cooling system could be low on coolant. Which technician is correct? a. Technician A only b. Technician B only c. Both Technicians A and B d. Neither Technician A nor B

b. Technician B

Airflow through a typical HVAC system is being in discussed. Technician A says that outside air is always used in all heating and cooling positions. Technician B says that the temperature is controlled by blending airflow through the evaporator and heater core. Which technician is correct? a. Technician A only b. Technician B only c. Both Technicians A and B d. Neither Technician A nor B

b. Technician B

A customer complains that the heater works sometimes, but sometimes only cold air comes out while driving. Technician A says that the water pump is defective. Technician B says that the cooling system could be low on coolant. Which technician is correct? a. Technician A only b. Technician B only c. Both Technicians A and B d. Neither Technician A nor B

b. Technician B only

Technician A says that all HFC-134a uses the same refrigerant oil. Technician B says that refrigerant oil, regardless of type, must be kept in a sealed container to keep it from absorbing moisture from the air. Which technician is correct? a. Technician A only b. Technician B only c. Both Technicians A and B d. Neither Technician A nor B

b. Technician B only

Technician A says that all orifice tube on all vehicles use the same orifice. Technician B says that orifice tubes vary the orifice size by application. Which technician is correct? a. Technician A only b. Technician B only c. Both Technicians A and B d. Neither Technician A nor B

b. Technician B only

Technician A says that heat is measured in degrees. Technician B says that temperature is measured in degrees. Which technician is correct? a. Technician A only b. Technician B only c. Both Technicians A and B d. Neither Technician A nor B

b. Technician B only

Technician A says that one heater hose should be hot and the other hose cool if the heater is functioning okay. Technician B says that both hoses should be hot to the touch. Which technician is correct? a. Technician A only b. Technician B only c. Both Technicians A and B d. Neither Technician A nor B

b. Technician B only

The last step in the diagnostic procedure is _____________. a. Determine the root cause b. Verify the repair c. Recharge the system d. Perform a visual inspection

b. Verify the repair

Nothing is seen in the sight glass. Technician A says that the system may be completely empty of refrigerant. Technician B says that the system may be completely charged. Which technician is correct? a. Technician A only b. Technician B only c. Both Technicians A and B d. Neither Technician A nor B

c. Both Technicians A and B

Technician A says that evaporator leaks can be detected by installing dye into the system and looking for yellowish-green dye stains. Technician B says that a leak at the evaporator can be detected by removing the blower motor resistor pack and inserting an electronic leak detector probe into the air stream. Which technician is correct? a. Technician A only b. Technician B only c. Both Technicians A and B d. Neither Technician A nor B

c. Both Technicians A and B

Technician A says that some cabin filters are accessible behind the glove compartment. Technician B says that some cabin filters are accessible from under the hood. Which technician is correct? a. Technician A only b. Technician B only c. Both Technicians A and B d. Neither Technician A nor B

c. Both Technicians A and B

Technician A says that with a properly operating air-conditioning system, the inlet to the compressor should be cold and the outlet from the compressor hot. Technician B says that the condenser should be hot and the evaporator cold. Which technician is correct? a. Technician A only b. Technician B only c. Both Technicians A and B d. Neither Technician A nor B

c. Both Technicians A and B

A defective thermostat can cause the engine to operate_________. a. Too cold b. Too hot c. Either a or b d. Neither a nor b

c. Either a or b

What type of service valves are used with R-134a? a. Schrader valves b. Gate valves c. Quick-disconnect valves d. Saddle valves

c. Quick-disconnect valves

Which is not part of a rear air-conditioning system? a. Rear evaporator b. Rear heater core c. Rear AC compressor d. Rear blower motor

c. Rear AC compressor

Which reading represents the lowest vacuum readings? a. 27 in. Hg b. 28 in. Hg c. 29 in. Hg d. 500 microns

d. 500 microns

Which position on the climate control panel should the driver select to avoid having the air-conditioning compressor turn on? a. Heat b. Defrost c. A/C d. Both a and b

d. Both a and b

O-rings are usually made from ___________. a. HSN b. Natural rubber c. Neoprene d. Either a or c

d. Either a or c

The first step in the diagnostic procedure when attempting to solve an HVAC customer problem is _____________. a. Visual inspection b. Check for diagnostic trouble codes c. Check for technical service bulletins d. Verify customer concern

d. Verify customer concern