ASE A7 Heating and AC Practice Exam

A CCOT system has a high high side pressure. Technician A says to suspect the thermostatic expansion valve. Technician B says this system contains an orifice tube. Who is correct?

• Technician A only
• Technician B only
• Both Technician A and B
• Neither Technician A nor B

Corrosion at point A of the electrical diagram above will result in:

• Excessive resistance in the splice leading to the high pressure sensor.
• Voltage drop at the connector of the signal circuit for the high pressure sensor.
• Excessive resistance in the reference circuit of the high pressure sensor.
• Voltage drop at the connector of the ground circuit for the high pressure sensor.

A vehicle's air conditioning performance is reduced at low speeds and stop lights, but cools at highway speeds. Which of these is MOST likely the cause of this condition?

• A low refriderant charge.
• A missing fan shroud.
• A normal condition.
• A faulty compressore clutch relay.

Two technicians are discussing an inoperative electric blend door in an automatic air conditioning system. Technician A says to inspect the blend door's wiring and connections for an open circuit. Technician B says to troubleshoot this circuit with a test light. Who is correct?

• Technician A only
• Technician B only
• Both Technician A and B
• Neither Technician A nor B

A squeal is heard only when the compressor clutch first engages. Technician A says this is caused by a loose serpentine belt. Technician B says this is caused by a worn clutch pulley bearing. Who is correct?

• Technician A only
• Technician B only
• Both Technician A and B
• Neither Technician A nor B

Component A in the electrical diagram above has all of the following characteristics EXCEPT:

• It is a negative temperature Coeffiicient sensor.
• It is a thermistor.
• It is a variable resistor.
• It is a switch

A frozen spot is noticed in the center of the condenser. Technician A says a frozen spot on a component or connection indicates a restriction in the system. Technician B says this is caused by a clogged orifice tube. Who is correct?

• Technician A only
• Technician B only
• Both Technician A and B
• Neither Technician A nor B

A technician is diagnosing a vehicle's air conditioning system. The vehicle has good engine performance, but the air conditioner is blowing warm air only. A yellow substance is noticed around the evaporator case drip tube. Technician A says this is coolant leaking from the heater core. Technician B says this is fluorescent dye leaking from the evaporator core. Which technician is MOST likely correct?

• Technician A only
• Technician B only
• Both Technician A and B
• Neither Technician A nor B

R 134a Refrigerant:

• Changes from a vapor to a liquid as it absorbs heat.
• Containers are sky blue colored.
• Has a very high boiling point.
• Is a CFC that contains chlorine.

Two technicians are discussing electric cooling fans and air conditioning performance. Technician A says electric fans regulate refrigerant temperatures more precisely than belt driven fans do. Technician B says electric cooling fans are controlled by control modules that use temperature and pressure actuated sensors and switches. Who is correct?

• Technician A only
• Technician B only
• Both Technician A and B
• Neither Technician A nor B