Ac test

A vehicle with automatic climate control stays on high blower and maximum cooling at all times. Tech A says that a failed sun load sensor could be the cause. Tech B says that excessive refrigerant charge could be the cause. Who is right? A. Tech A B. Tech B C. Both D. Neither

Answer: A

After the battery was replaced, the air-conditioning door motors in the HVAC system had to be initialized. This means that the HVAC computer needed to: A. Reestablish the door position reference B. Verify that the motors would operate in both directions C. Measure the motor current draw D. Test the motors for possible faults

Answer: A

An AC system has been completely charged. The high side gauge reading is HIGHER than normal, and the low side gauge is LOWER than normal. Which of these could be the cause? A. A restricted orifice tube B. A bad compressor C. A leaking condenser D. An inoperative cooling fan

Answer: A

An air conditioning system is being diagnosed for rapid compressor clutch cycling. Tech A says that low refrigerant could be the cause. Tech B says that restricted condenser airflow could be the cause. A. Tech A B. Tech B C. Both D. Neither

Answer: A

During hard acceleration, the dash outlet air switches to the defrost vents. Which of these is the most likely cause? A. A faulty vacuum check valve B. Misadjusted controls. C. A stuck blend door D. Restricted exhaust

Answer: A

In an AC system, refrigerant boils in the: A. Evaporator B. Condenser C. Compressor D. Accumulator

Answer: A

Tech A says that on many vehicles, the electric condenser fan may run anytime the AC compressor is running. Tech B says that on many vehicles, the electric condenser fan cycles OFF and ON while the AC compressor runs. Who is right? A. Tech A B. Tech B C. Both D. Neither

Answer: A

The OE (original equipment) refrigerants in automobile AC systems: A. Have a low boiling point B. Have a high moisture content C. Are highly toxic D. Are highly flammable

Answer: A

The air coming out of the vents is too warm on a vehicle equipped with an automatic AC control system. The most likely cause is a faulty: A. Blend-air door control B. Outside air door control C. Recirculate air door control D. Defroster air door control

Answer: A

The best place to find information on how to handle a dangerous chemical is the: A. SDS sheet B. Product label C. Product catalog D. Product container

Answer: A

The purpose of the diode in the illustrated air-conditioning clutch coil wiring diagram is to: A. Prevent voltage spikes as the clutch coil disengages B. Prevent clutch coil overheating C. Prevent opening of the pressure switch at normal pressures D. Prevent A/C engagement when in "heat" mode

Answer: A

33. Frost appears at the orifice tube inlet of an AC system that is cooling poorly. Which of these is the most likely cause? A. A low refrigerant charge B. A restricted liquid line C. A slipping clutch D. A plugged accumulator

Answer: B

A customer complains that the AC does not cool sufficiently, and the engine temperature rises at slow vehicle speeds. Which of these is the most likely cause? A. Open thermostat B. Inoperative cooling fan C. Low coolant D. Defective AC compressor

Answer: B

A neglected cabin air flow filter can cause: A. A film on the inside of the windshield B. A musty smelling interior C. High A/C system gauge readings D. Leaking heater core

Answer: B

A technician is preparing to charge the AC system on a vehicle that has had the condenser replaced as a part of a front end collision repair. The technician should: A. Evacuate and recharge the system B. Identify refrigerant type; correct the refrigerant oil level; evacuate and recharge the system C. Change the refrigerant oil; evacuate and recharge the system D. Identify the refrigerant type and recharge the system

Answer: B

An AC drive belt makes a "chirping" noise only with the AC on. Which of these could be the cause? A. Faulty AC clutch diode B. Incorrect pulley alignment C. Low refrigerant charge D. Incorrect refrigerant type

Answer: B

An AC system does not cool as well as it once did. A technician observes constant bubbles in the sight glass. What could this indicate? A. A correct charge B. Low refrigerant charge C. An over-charge of refrigerant D. A ruptured desiccant bag

Answer: B

An air conditioning compressor is being replaced. Tech A says all refrigerant oils are inter- changeable with one another. Tech B says that new replacement compressors should have their oil level verified. Who is correct? A. Tech A B. Tech B C. Both D. Neither

Answer: B

An engine runs hot and has poor AC performance at highway speeds. Tech A says that a stuck open engine thermostat could be the cause. Tech B says that a missing air dam could be the cause. Who is correct? A. Tech A B. Tech B C. Both D. Neither

Answer: B

The purpose of a radiator fan shroud is to increase: A. Cooling efficiency at highway speeds B. Cooling efficiency at low vehicle speeds C. AC system pressure at highway speeds D. AC system pressure at low vehicle speeds

Answer: B

When replacing a failed AC compressor clutch, a technician should: A. Determine the compressor oil level and viscosity B. Check voltage drop on the clutch's power and ground circuits C. Eliminate all clutch air-gap to reduce slippage D. Reduce refrigerant by 10 and add leak detection dye

Answer: B

While driving on very hot and humid days, clear water drips out from under the dash onto the passenger side floor. Tech A says that a clogged hot water control valve could be the cause. Tech B says that a clogged evaporator case drain could be the cause. Who is correct? A. Tech A B. Tech B C. Both D. Neither

Answer: B

An AC compressor clutch slips on engagement. Tech A says that high resistance at the clutch ground could be the cause. Tech B says that high resistance in the clutch coil could be the cause. Who is correct? A. Tech A B. Tech B C. Both D. Neither

Answer: C

Tech A says that a radiator cap should be pressure tested as part of a cooling system test. Tech B says that hoses should be checked for ballooning while performing a cooling system pressure test. Who is right? A. Tech A B. Tech B C. Both D. Neither

Answer: C

Tech A says that an overcharged AC system can cause excessive compressor noise. Tech B says that an undercharged AC system can cause excessive AC clutch engagement/disengagement. Who is right? A. Tech A B. Tech B C. Both D. Neither

Answer: C

Tech A says that each piece of recovery equipment should be designated to recover only one particular refrigerant. Tech B says that R-134a and R-12 service fittings are not interchangeable. Who is correct? A. Tech A B. Tech B C. Both D. Neither

Answer: C

Tech A says that in an AC evaporator, liquid refrigerant becomes a gas. Tech B says that in an AC condenser, gaseous refrigerant becomes a liquid. Who is correct? A. Tech A B. Tech B C. Both D. Neither

Answer: C

The AC clutch in the illustration circuit does not engage with the AC mode selected. Voltage measured at points X and Y is 12 volts. Which of these is the most likely cause? A. Fuse A is open B. Fuse B is blown C. The PCM is not grounding the A/C relay D. The A/C relay coil has an open circuit

Answer: C

The amount of refrigerant used to charge an A/C system is measured by: A. Pressure B. Temperature C. Weight D. Volume

Answer: C

The following question contains the word EXCEPT. Heat can be transferred by each of these methods EXCEPT: A. Conduction B. Convection C. Compression D. Radiation

Answer: C

The purpose of a clamping diode in an AC compressor clutch circuit is to: A. Maintain clutch coil current draw B. Protect the clutch coil C. Protect the PCM D. Provide AC status data to the PCM

Answer: C

Which of these organizations issues regulations for the handling, storage, and recycling of refrigerants? A. OSHA B. NIOSH C. EPA D. SAE

Answer: C

A heater blower operates on HIGH speed only. The most likely cause is a failed: A. Control head B. Blend door actuator C. Blower ground circuit D. Blower resistor

Answer: D

A technician finds that a vehicles AC system has a low refrigerant charge. What should be done before charging the system? A. Evacuate the complete system B. Add 2 ounces of refrigerant oil C. Recycle the remaining refrigerant D. Identify the refrigerant type

Answer: D

Tech A says the high side AC lines and hoses should be cool or cold to the touch while the AC system is running. Tech B says that the low side AC lines and hoses should be warm or hot to the touch while the system is running. Who is correct? A. Tech A B. Tech B C. Both D. Neither

Answer: D

The following question contains the word EXCEPT. An automatic AC system may contain all of these EXCEPT: A. A sun-load sensor B. An in car temperature sensor C. An outside temperature sensor D. A coolant level sensor

Answer: D

Which of these procedures may be required when replacing a seized AC compressor? A. Flush the system with CO2 B. Replace the evaporator core C. Flush the condenser with water D. Replace the accumulator/receiver drier

Answer: D

Which procedure should a technician do FIRST when diagnosing an AC system? A. Disarm the airbag B. Install a refrigerant identifier C. Inspect for a previous retrofit D. Verify the complaint

Answer: D