AUTT Ch 64 Heating and Air-Conditioning System Diagnosis

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

A) True

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

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. Who is right? A) Technician A only B) Technician B only C) Both technicians A and B D) Neither technician A nor B

B) Technician B only

Airflow through a typical HVAC system is being 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 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 D) Neither technician

B) Technician B only

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 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

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

The last step in the diagnostic procedure is ________. A) Determine the root cause B) Perform a visual inspection C) Recharge the system D) Verify the repair

D) Verify the repair