A/C final written
The two functions of the receiver-drier are?
- Absorb moisture & Separate gas from liquid
What is the typical blower resistance at medium high speed _____
.3 ohms, 8-9V
Humans prefer relative humidity that is between_____and_____.
45% and 55%
Tech A says that a 180 F thermostat should be fully open at 195 F. Tech B states that at higher temperatures will decrease the amount of coolant in the system.
A only
BTU
British Thermal Unit
What is the scientific name for R-152a?
Difluoromethane
Coolant is hottest in which area:
Near the thermostat
Most R-134a refrigeration systems use _____ oil for lubrication.
Polyalkylene Glycol
What type of oil is specified for R-1234yf systems?
Polyalkylene Glycol with additive
Engine too cold can cause
Poor atomization, Sludge, Poor vaporization
Three states of Matter?
Solid, Liquid, Gas
Where is the ozone layer?
Stratosphere
A thermistor is a _____ sensitive resistor
Temperature
The first worldwide effort to limit the use of ozone-depleting chemicals has become known as _____
The Montreal Protocol
Cold is...
The absence of heat
Latent heat of fusion for water is:
The addition of 144 BTU of heat to change 1 lb. of ice at 32 F into water at 32 F
Define TED:
Thermal Electric Device
Refrigerants absorb heat:
While changing from a liquid state to a gaseous state
Air management system contains: - doors - plenum - ducts - all of the above
all of the baove
ATC temperature control: - uses input from driver to maintain temperature - uses servo to maintain temperature location - uses sensors to maintain temperature in vehicle - all of them
all of them
Just watching is not enough
nana ka maka, hana ka lima
Blower speed is controlled by:
placing electrical resistance to the circuit
The water pump uses which of these reactionary forces to circulate the coolant? - Centripetal force - Gravitational force - Centrifugal force - Magnetic force
Centrifugal force
_____is thought to be the chemical chiefly responsible for depletion of the ozone layer.
Chlorine
What is the scientific name for R-12?
Chlorofluorocarbon
Snoopy states that the snowflake button is used to defrost snow that falls on the glass. Clifford the big red dog states that high resistance in a circuit could cause slow motor operation. Who is correct?
Clifford
Tech A says that normal coolant temperatures are between 220 F and 270 F. Tech B states that pH buffers reduce electrolyte corrosion. Who is correct?
B only
Tech A states that refrigerant should be recovered and recycled if you suspect contamination. Tech B states that air condition uses a muffler to reduce vibration. Who is correct?
B only
Tech A states that the line running to the compressor from the evaporator is called the discharge line. Tech B states that the line running from the receiver dryer to the TXV is the liquid line. Who is correct?
B only
Technician A states that Buna o-rings are used in R134a systems Technician B states that Neoprene o-rings can be used in R-12 systems
B only
Technician A states that an orifice is an improved design of the TXV. Technician B states that Scroll and vane compressors are both rotary compressors. Who is correct?
B only
Technician A states that the compressor is shut off if temperature at the evaporator drops to 35 F. Technician B states that some A/C systems may have 2 thermal expansion valves
B only
Most compressors have an oil pump?
False
Reciprocating compressors can use a Scroll? True or False
False
Variable displacement compressors afford the smoothest operation and cycles its clutch in order to maintain a constant 32 F evaporator temperature.
False
If the upper radiator hose collapses when the engine cools what is the most likely cause?
Faulty pressure cap
When determining electric door motor positions the ECM uses
Feedback Circuit
O ke kahua mua, ma hope ke kukulu
First the foundation is built, then you build the house.
Most heating and A/C systems are designed so that if the controls fail the system will will operate at... - Wherever it was last set - Max cool - Full heat and defrost - None of the above
Full heat and defrost
What happens in the condenser
Gas changes to liquid
I ha'aheo no ka lawai'a i ka lako i ka 'upena
Good tools help the worker succeed, A fisherman is proud when provided nets
What color(s) are used to identify a container used for contaminated or unknown refrigerant
Gray with yellow at the top
Besides the ambient sensor, what are two other major temperature sensors used in determining ATC system operation.
In vehicle temp sensor, engine temp sensor
Pressurizing the automotive cooling system results in _____.
Increased coolant boiling point
During A/C operation, the compressor...
Inlet is cold/outlet is hot
A tank into which the refrigerant is recovered must be_____every_____years.
Inspected, 5 years
How many Electrons are in the following: (Write the material and its number) Insulator: _____ Conductor: _____ Semi-Conductor:_____
Insulator: Rubber >4 Conductor: Copper <4 Semi-Conductor: Silicone =4
Two technicians are discussing heat movement. Mr. Nagamine says that heat is a form of energy. Elmer says Mr. Nagamine does not know anything and that heat travels away from cold. Which technician is correct?
Mr. Nagamine
Mr. Nagamine states that a network that runs at 100,000 bps is a Class B. Mr. Nitta states that a Class C system can run at 500,000 bps. Who is correct?
Mr. Nagamine only
To convert Celsius to Fahrenheit:
Multiply by 2, then add 25
Mr Maile states that Andre Simon Volta discovered the volt. Mr Gold states that General Motors discovered the volt. Who is correct?
Neither
Tech A states that a circuit breaker always needs to be reset. Tech B states that Low/Low pressures means system over charge, Who is correct?
Neither
List 2 types of condenser flows:
Parallel and Serpentine
What toxic gas is formed when R-12 comes in contact with flame?
Phosgene
What are 4 potential safety hazards when working with refrigerant?
Poison, Combustion, Physiological Reaction, Explosion, Blindness, Asphyxiation, Frostbite
Electric cooling fans are typically commanded on and off by the _____
Powertrain control module (PCM)
Many modern systems use an engine temperature sensor that...
Prevents heater operation until the coolant is hot.
If cooling system operates at too cool of a temperature, the engine will _____
Produce higher emissions
Lockstitch & spiral are types of _____ _____
Radiator Hoses
An ambient sensor for an ATC system is usually mounted...
Radiator shroud
Door operating motors may have operation strategies, they are called:
Smart Motors
What type of blower fan is used in modern A/C systems?
Squirrel type
What are the names of the 2 lines that enter and leave the compressor?
Suction line & discharge line
List 3 types of sensors that can be used in ATC systems
Sun load, Interior, Ambient air
List three types of reciprocating piston compressors:
Swash plate, crankshaft, Wobble plate
What is true about thermostats
The temperature marked on the thermostat is a temperature at which the thermostat should start to open
A main source of heat used to warm the passenger compartment is _____.
The vehicle engine
What is the purpose of the heater core?
Transfers heat from the engine to the air in the vehicle
The global warming potential (GWP) of a refrigerant is a measure of the refrigerant's ability to _____.
Trap Heat
Depending on the particular pressure cycling seitch, the cutour pressure could be between: 22 and 25 psi. True or False?
True
Expanding a volume aof gas over a larger area will lower its temperature, True or False?
True
In an ATC system when the driver selects mac heat of max cool immediately following start-up of the vehicle, the air coming out of the vents _____ be the desired temperature. - may - will not - will - none of the above
will not
SNAP=
Significant New Alternative Policy
List three things that a too cold engine can cause:
Slidge, Poor oil flow, Poor fuel vaporization/atomization, Knocking
Because R-1234yf refrigerant is _____, special equipment is required.
Slightly Flammable
On most ATC systems what is used to create air flow across the in/car temp sensor?
Aspirator
Negative effects of water as engine coolant
Causes corrosion, too low boiling point, too high freezing point
Within the receiver-drier, where is the outlet pickup end located
At the bottom of the dryer so that only liquid goes to the expansion valve
Refrigerant enters the condenser:
At the top and exists at the bottom
Within the accumulator, where is the outlet pickup end located and why?
At the top so that it does not pick up liquid and send it to the compressor.
The freezing poing of water is _____ on the Celcius scale.
0 degrees
What is the typical blower resistance at high speed _____
0 ohms
(Rule of Thumb) How much oil should be added when replacing a Receiver Drier?
0.5oz
ODP of CFC
0.8-1
GWP of R-12
10,900
Radiator pressure caps are rates at _____
15psi
(Rule of Thumb) How much oil should be added when replacing a condenser?
1oz
List possible uses of the following Servos: 2 wire: 3 wire: 5: wire
2 wire: Fresh recirc 3 wire: Defrost/Bi level 5 wire: Blend air door
The boiling point of water is _____ on the Fahrenheit scale
212 degrees
One BTU is equal to _____ calories.
252
(Rule of Thumb) How much oil should be added when replacing an Evaporator?
2oz
(Rule of thumb) How much oil should be added when replacing an Accumulator?
2oz
What is the Rule of Thumb reading of a clutch resistance?
3-4 ohms
100 degrees F is about _____ degrees C
38
Most systems use a flap door that swings about _____ degrees
45-90
What is the typical blower voltage at the lowest speed _____
4V/ 1.5-2 ohm
Humans prefer temperatures that are between _____ and _____.
68F and 78F
What is the typical blower voltage at medium-low speed _____
6V/ 1 ohm
Select all that are correct: The inlet hose to the heater core connects to... - A connection near the thermostat - A connection at the radiator inlet - Water pump inlet - An area with the highest coolant pressure
A connection near the thermostat, An area with the highest coolant pressure
Tech A says that an ECT is a NTC. Tech B states that a Solar Sensor is a NTC. Who is correct?
A only
Tech A says that corrosion inhibitors affects pump seals. Tech B states that Ethylene reduces the boiling point & increases the Freezing point. Who is correct?
A only
Tech A says that vehicles have on coolant temperature sensor. Tech B states that all vehicles have two coolant temperature sensors. Who is correct?
A only
Technician A states that A/C pope diameter is its inner diameter Technician B states that #6 pipe has a 3/8' diameter
A only
Technician A states that a bad accumulator could cause slugging. Technician B states that Refrigerant enters the condenser as a liquid.
A only
Technician A states that a free spinning fan before first start up could be due to a failed fan clutch. Technician B states that if an electric fan fails and pressures build up to 350 in the high side, that could mean the compressor is defective.
A only
Technician A states that when a compressor is changed the oil level should be checked. Technician V states that oil from old compressor can be reused. Who is correct?
A only
Technician A states that when removing orifice, a special tool needs to be used. Technician B states that Condenser, compressor, and hose replacement will probably need to be changed when performing a retrofit on late model systems
A only
Two technicians are discussing a dual zone front A/C system. Technician A states that front dual A/C systems usually have two doors. Technician B states that the temperature difference between the 2 sides can only be up to 20 F.
A only
An orifice tube is:
A unit with a fixed diameter
A measurement of the actual weight of water in a given volume of air is ______
Absolute humidity
The amount of water that air can hold depends on_____.
Absolute pressure and temperature
The three functions of the accumulator are:
Absorb moisture, Separate liquid and gasses, and protect the compressor
Coolant flush machine is helpful in preventing _____ from entering the cooling system.
Air
The door that controls what source of air enters into the vehicle's plenum is called:
Air inlet door
A/C performance test shows good high and low side pressures, but the air discharge at the air ducts is not as cold as it should be: - Blend air door out of adjustment - Leaking vacuum hose - Actuator motor disconnected - All of the above
All of the above
Heater hose inside diameter is _____" -10/16 -6/8 -1/2 -all of the above
All of the above
Recirculation, mode direction, and air temperatures is controlled by: - Modules - Cables - Servos - All of the above
All of the above
Heater flow control vavles are used to
Allow heater output temperature to be adjusted, Heater to be shut off
Good tools help the worker succeed, A fisherman is proud when provided nets
I ha'aheo no ka lawai'a i ka lako i ka 'upena
Aoa states that an orifice could be a variable valve. Ferdinand states that only a TXV can be variable valve. Who is correct?
Aoa
Aoa states that modern cooling systems can maintain temperatures between 180 and 230 F. Laa states that moder cooling systems can maintain temperatures at 270 F. Who is correct?
Aoa only
What type of refrigerant hose is used with an R-134a system?
Barrier hoses
Where is the TXV located?
Between the high and low sides of the A/C lines
Volume of air flowing in the vehicle is controlled by the _____
Blower motor
In a vehicle with a rear A/C system, list what A/C components would be located in the rear assembly?
Blower motor, Evaporator, Expansion valve, pipes
Scooby Doo states that vehicles use a coolant flow valve to control heater output temperature. Superman states that Scooby don't know anything and that vehicles use vacuum to control heater temperature. Who is correct?
Both
Tech A says that air temperatures are controlled by cables. Technician B states that air temperatures are controlled by diaphragms. Who is correct?
Both
Technician A states that a rapid cycling clutch is due to low refrigerant. Technician B states that a rapid cycling clutch is due to excessive clutch clearance.
Both A and B
Technician A states that wobble plate compressors use 5 pistons. Technician B states that wobble plate compressors use 7 pistons. Who is correct?
Both A and B
Two technicians are discussing Section 609 of the Clean Air Act. Technician A says that it requires that technicians be properly trained and certified. Technician B says Section 609 requires that recovery and recycling equipment be of an approved type. Which technician is correct?
Both A and B
MVAC=
Mobile Ventilation Air Conditioning
Tech A states that cooling fans are designed to draw air through the radiator to aid in the heat transfer process. Tech B states that drawing the heat from the coolant transfers this heat to the outside air through the radiator. Who is correct?
Both Tech A and B
Arthur states that undercharge can cause an A/C system produce less than normal cooling. La'akea states that you should not listen to Arthur because an overcharge of refrigerant can cause an A/C system to produce less than normal cooling. Who is correct?
Both of them
Micah states that #4 tubing has a diameter of 1/4' Grayson states that Micah don't know what he is talking about because 8mm tubing is a #6
Both of them
Explain the process of how R-12 affects the Ozone
CFC is released into environment and breaks up from rain and sun. Cl and CF are formed. Cl binds with O3=CLO and O2
One drawback of using CO2 (R-744) as a refrigerant is _____.
CO2 system pressures are extremely high
Many late model vehicles use a(an)_____to help clean the air in the vehicle.
Cabin filter
List 3 ways in which an air door can be operated
Cable, Servo, Vacuum
What is the scientific name for R-744?
Carbon Dioxide
When heat is transferred through material, from one molecule to the one next to it this is called?
Conduction
The outlet hose from the heater core connects to...
Connection with the least coolant pressure, A connection near the water pump inlet
CAN means:
Controller Area Network
List 3 reasons why pure water is not the best liquid to use in the radiator:
Corrosion, High freezing point, Low boiling point
Two ways in which coolant flows through radiators:
Cross flow & Down flow
In a series circuit what is constant:
Current
List 3 tests that can be used to inspect for a blown head gasket:
Cylinder leakage, Block tester, Compression test, Vacuum gauge
List readings of the solar sensor when in the following conditions: Vehicle in the dark: _____ Vehicle in the sun: _____
Dark: 0.3 Bright: 3
In addition to cooling the passenger compartment, an air conditioning system_____/
Dehumidifies air
Radiators are: - Up flow - Down flow - Vapor flow - Reverse flow
Down flow
List three doors that control air flow in an A/C system
Mode, Blend/temp, Recirc/inlet
FMVSS 103 states that: - Only pertains to passenger vehicles - Defogger operates if compressor binding - Each vehicle must have a defogger system - Defogger should work at least when it's cold outside
Each vehicle must have a defogger system
Two types of cooling fans
Electric cooling fans, Mechanical clutch type cooling fans
An automotive engine that is running too high of a temperature will have which of these?
Excessive oil consumption
What kind of metering device does a system with receiver dryer have?
Expansion valve
All coolants need to be diluted before refilling cooling system. True or False
False
Barrier hoses are made up of:
Has 1 or 2 non-permeable inner layers with internal reinforcement and an outer later for protection
He Man says that some coolants can be used straight from the bottle. Skeletor states that all coolant needs to be mixed with water. Who is correct?
He Man only
What is Latent Heat
Heat required to change a state of matter
What is sensible heat?
Heat that can be felt/ Heat that can be measured
Heat intensity refers to which of the following?
Heat that individuals feel
Name 4 components in a Heater/ Cooling system
Heater core, Radiator, Waterpump, Thermostat
Fill the blanks with the correct components. The heating system includes the _____, _____, and in some applications a _____.
Heater core, hoses, water pump, control valve, blower motor, heating pads
The receiver drier is located on the _____ pressure side of the system.
High
Name two conditions that a refrigerant overcharge will create.
High pressures, warmer A/C lines
In any A/C system, which line has the smallest diameter?
High side
The amount of moisture contained in the air is called_____.
Humidity
What is the scientific name for R-22?
Hydrochloroflurocarbon
What is the scientific name for R-134a?
Hydrofluorocarbon
A new refrigerant, required to be used in the USA beginning in year 2021, is_____.
Hydrofluro-olefin
What is the scientific name for R-1234yf?
Hydrofluro-olefin
The heater vore outlet is usually _____ than the inlet
Larger/ Cooler
R-134a is in what color container?
Light Blue
In the Evaporator, the A/C system changes the refrigerant from a _____ to a _____
Liquid/mist to a Gas
When you smell the smell
Look around
The low side contains refrigerant that is at a
Low pressure, Low temperature, Gas, and Liquid
The low pressure side of any A/C system produces...
Low pressures and cool temperatures
In all cycling clutch systems, the compressor is cycled regularly to control...
Low side temperature above 32 degrees F
Global warming potential (GWP) is decreased if a gas has a _____ GWP number.
Lower
When one works one learns
Ma ka hana ka 'ike
In a variable compressor, when cooling is needed the compressor is at what position?
Max angle position
List 4 function that the mode servo could control
Max/Face, bi directional, Defroster, Feet
How does a TXV operate? What causes the valve to open?
Meters the amount of refrigerant that goes to the evaporator, runs off of temperature at the evap. lines and opens and closes depending on temperature at the evaporator
Technician A says that 1 calorie of heat can increase the temperature of 1g of water by 1 degree F. Technician B says that absolute humidity is the amount of water vapor that air can hold. Which technician is correct?
Neither
Tech A states that Air Quality Sensors detect Cl and RH. Tech B states that at night Sun Load sensors should read around 3V. Who is correct?
Neither A nor B
Tech A states that the Outside ambient Air Temp Sensor is mounted on the compressor. Tech B states that a malfunctioning A/C control system that sets DTC's, can only be checked via OBD2 scanner.
Neither A nor B
Tech A states that the cooling system should be tested for leaks using an air-operated pressure pump. Tech B states that the freezing and boiling point of coolant can be tested using a thermometer. Who is correct?
Neither A nor B
Technician A states that Swash plate and Wobble plate are two names for the same compressor. Technician B states that compressor ratios range between: 3-9:1
Neither A nor B
Technician A states that all swash plate compressors have 3 pistons Technician B states that vane compressors have 3 pistons
Neither A nor B
Technician A states that inline filters should be installed in the low side. Technician B states that The high side port can be located on the Accumulator. Who is correct?
Neither A nor B
Tech Z states that the cooling fan relay is controlled by the BCM. Tech Y states that a scanner is needed to diagnose A/C trouble codes
Neither Y nor Z
Tech A states that heater hoses at both sides of the control valve should always be the same temperature at all times. Tech B states that Latent heat of Vaporization is 144BTU. Who is correct?
None
One way check valves and vacuum reservoirs are used to: - to control door position during acceleration - none of them - all of them - to hold door position during normal operation - to reduce hissing noise during operation
None of them
Mickey states that a cooling system can be pressure testes using an air gun. Minnie states that air guns are dumb and that you need a thermometer to pressure test the cooling system. Who is correct?
None of them are correct
Technician A states that Pusher type cooling fans are mounted in the back of the radiator. Technician B states that Puller type cooling fans are mounted in the front of the radiator. Who is correct?
None of them are correct?
E unuhi: First build the foundation, then build the house
O ke kahua mua, ma hope ke kukulu
E unuhi: First the foundation, then build the house
O ke kahua mua, ma hope ke kukulu
What kind of metering device does a system with an accumulator have?
Orifice Tube type
When an A/C compressor is on, the _____ is hot to the touch
Outlet/ Discharge
The purpose of air conditioning is to _____.
Removes pollen and dust, Removes moisture, Removes heat
List 3 types of clamps
Screw, spring, whittek
One possible new type of vehicle air conditioning system is the_____system
Secondary Loop
In a non-cycling clutch system, evaporator freeze up is prevented by controlling...
TXV cycling
Tech A states that the purpose and the function of the cooling system is to maintain proper engine operating temperature. Tech B states that the water pump controls engine coolant temperature by opening at its rates opening temperature to allow coolant to flow through the radiator. Which Tech is correct?
Tech A
Tech A states that a malfunctioning heater could be due to leaking heater core. Tech B states that coolant is hottest at the lower radiator hose. Who is correct?
Tech A only
Customer comes in complaining that heater is not as warm as it was before, the vehicle has been running, and all radiator and heater hoses are at 160 F. Tech A says that the heater core is plugged. Tech B says that the thermostat must be stuck open. Who is correct?
Tech B
Technician A says that the freezing point of a substance is the temperature at which the substance changes state from a solid to a liquid. Technician B says that the freezing point of a substance is the temperature at which the substance changes state from a liquid to a solid. Which technician is correct
Tech B
Technician A says that mixing small amounts of refrigerant is acceptable according to the EPA. Technician B says that each refrigerant must have unique fittings to reduce accidental mixing of refrigerants. Which technician is correct?
Tech B only
Tech Z states that the smallest particle is called Matter. Tech Y states that in a multiplexing system, twisted wires should be repaired in pairs
Tech Y
List 3 ways to check for belt tension
Tension gauge, torque wrench, deflection 1/2"
The cut-in pressure is about 42 to 49 psi again depending on the particular pressure switch? True or False
True
The ozone later primarily filters what type of radiation?
Ultra Violet
What type of component is this? be specific
Vacuum Coolant Control Valve
Superheat is the process of:
Vapor whose temperature rises above it's boiling point
Ma ka hana ka 'ike
When one works one learns
E Unuhi: Ma Ka Hana ka 'ike
When one works, one learns
What color container is used for R-1234yf refrigerant?
White with red stripe
What does the FMVSS 103 state?
Will default to defroster if control unit is faulty
Heat
Will transfer through the air as convection, Will travel to a substance of less heat, Cannot be destroyed
On a normal 5 pin actuator list the common responsibilities of each of the 5 wires
power, ground, 5v, signal, feedback
