Question 1

Technician A says that a liquid antimicrobial deodorizer and disinfectant is used to eliminate odors in duct systems.Technician B says when a musty odor develops the odor causing mold and mildew must be eradicated.Who is correct? A) Technician A only B) Technician B only C) Both A and B D) Neither A nor B

Accepted Answer

Both technicians are correct. A liquid antimicrobial deodorizer and disinfectant can be used to eliminate odors in duct systems, and when a musty odor develops, the odor-causing mold and mildew must be eradicated.

Question 2

Technician A says a block or ladder diagrams are used to aid in troubleshooting air conditioning duct system faults.Technician Bsays the use of test lights is not recommended for under dash service.Who is correct? A) Technician A only B) Technician B only C) Both A and B D) Neither A nor B

Accepted Answer

Block or ladder diagrams are indeed helpful for troubleshooting air conditioning duct systems as they provide a simplified visual representation of the system's electrical circuits, aiding in identifying faults. The use of test lights under the dash is generally not recommended because they can potentially damage sensitive electronic components or airbag systems due to the electrical load they introduce.

Question 3

Electronic actuator motors are being discussed.Technician A says a potentiometer provides a door position signal to the programmer.Technician Bsays the programmer grounds one side of the energized motor circuit to stop the door movement.Who is correct? A) Technician A only B) Technician B only C) Both A and B D) Neither A nor B

Accepted Answer

The answer of Electronic actuator motors are being discussed.Technician A...

Question 4

Technician A says the greatest problem in servicing the case and ducts is lack of tools.Technician B says the greatest problem in servicing the case and ducts is lack of service information.Who is correct? A) Technician A only B) Technician B only C) Both A and B D) Neither A nor B

Accepted Answer

Technician B is correct in stating that the greatest problem in servicing the case and ducts is lack of service information. The lack of proper tools may cause problems, but the lack of information would hinder the technician's ability to use the tools properly. Therefore, Technician A is incorrect.

Question 5

Name the major components of the air distribution system.

Accepted Answer

The answer of Name the major components of the air...

Question 6

Dual zone duct systems are being discussed.Technician A says the passenger controls only the passenger side temperature door.Technician B says the driver may be in control of the rear passenger compartment temperature on some systems.Who is correct? A) Technician A only B) Technician B only C) Both A and B D) Neither A nor B

Accepted Answer

Both technicians are correct. In some dual zone duct systems, the passenger can only control the temperature on their side, while the driver may be able to control the temperature in the rear passenger compartment.

Question 7

It is necessary to drain the engine coolant before replacing
A) the blower motor.
B) the heater core.
C) the vacuum diaphragm.
D) all of the above.

Accepted Answer

The heater core is a part of the engine coolant system, therefore it is necessary to drain the engine coolant before replacing it. The blower motor and vacuum diaphragm are not connected to the engine coolant system and therefore do not require draining of the coolant.

Question 8

When should the cabin air filter be replaced if the vehicle is operated in dusty or high pollution conditions?
A) Every 3 months or 3,000 miles.
B) Once a year or every 12,000 miles.
C) Every 15,000 miles.
D) Every 30,000 miles.

Accepted Answer

The answer of When should the cabin air filter be...

Question 9

Technician A says a bi-directional mode door actuator may control the mode doors.Technician Bsays a positive pressure is usually maintained within the passenger compartment.Who is correct? A) Technician A only B) Technician B only C) Both A and B D) Neither A nor B

Accepted Answer

Technician A is correct that a bi-directional mode door actuator may control the mode doors. Technician B is also correct that a positive pressure is usually maintained within the passenger compartment. Therefore, both technicians are correct.

Question 10

An inoperative vacuum motor could be caused by all of the following,EXCEPT:
A) defective vacuum switch.
B) door cable misadjustment.
C) leaking reserve tank.
D) kinked hose.

Accepted Answer

Door cable misadjustment would not cause a vacuum motor to be inoperative, as it is related to the mechanical linkage or cable system controlling doors (such as in HVAC systems), rather than the vacuum system itself. The other options (defective vacuum switch, leaking reserve tank, and kinked hose) directly affect the vacuum pressure or flow, impacting the operation of a vacuum motor.

Question 11

Mode door adjustments are being discussed.Technician A says the vacuum motor can be adjusted for motor stroke.Technician B says a cable can be adjusted for full movement of the door.Who is correct? A) Technician A only B) Technician B only C) Both A and B D) Neither A nor B

Accepted Answer

The answer of Mode door adjustments are being discussed.Technician A...

Question 12

Technician A says a check valve allows flow in one direction only.Technician B says a check valve blocks flow in one direction only.Who is correct? A) Technician A only B) Technician B only C) Both A and B D) Neither A nor B

Accepted Answer

Both technicians are correct. A check valve allows flow in one direction and blocks flow in the opposite direction.

Question 13

Technician Asays the heater control valve is found in-line on the heater hose of most vehicles.Technician Bsays the evaporator may be found inside the engine compartment on some vehicles.Who is correct? A) Technician A only B) Technician B only C) Both A and B D) Neither A nor B

Accepted Answer

Technician A is correct because the heater control valve, which regulates the flow of hot engine coolant into the heater core, is indeed commonly found in-line on the heater hose in many vehicles. Technician B is also correct because, while less common, the evaporator, which is part of the vehicle's air conditioning system, can be located inside the engine compartment in some vehicle designs, though it is typically found inside the dashboard.

Question 14

The BILEVEL mode is being discussed.Technician A says air may be directed to the panel and floor in the cooling mode.Technician B says air may be directed to the panel and floor in the heating mode.Who is correct? A) Technician A only B) Technician B only C) Both A and B D) Neither A nor B

Accepted Answer

Both technicians are correct. In Bi-level mode, the air can be directed to both the panel and floor in both cooling and heating modes. Therefore, option C is the correct answer.

Question 15

Technician A says debris in the fresh air intake can contaminate the refrigerant.Technician Bsays cleaning the fresh air inlet should be part of a periodic preventative maintenance schedule.Who is correct? A) Technician A only B) Technician B only C) Both A and B D) Neither A nor B

Accepted Answer

Debris in the fresh air intake can affect air quality and HVAC system efficiency but does not contaminate the refrigerant, which is a closed system. Cleaning the fresh air inlet should indeed be part of periodic maintenance to ensure proper airflow and system efficiency, making Technician B correct.

Question 16

In the MAX cooling position the main source of air is from:
A) defrost air.
B) recirculated air.
C) outside air.
D) vent supply air.

Accepted Answer

In the MAX cooling position, the main source of air is from recirculated air. This is because recirculating the already cooled air inside the vehicle is more efficient for cooling than bringing in warmer outside air.

Question 17

What is the sytem called that allows for seperate dirver and front passenger temperature control?

Accepted Answer

The answer of What is the sytem called that allows...

Question 18

Rear heat/cool systems are being discussed.Technician A says this system has its controls in parallel with the front controls.Technician B says some units have the temperature selected by the front controls.Who is correct? A) Technician A only B) Technician B only C) Both A and B D) Neither A nor B

Accepted Answer

The answer of Rear heat/cool systems are being discussed.Technician A...

Question 19

Technician A says the best way to determine the condition of vacuum hoses is by visual inspection.Technician B says a vacuum leak can often be heard.Who is correct? A) Technician A only B) Technician B only C) Both A and B D) Neither A nor B

Accepted Answer

Both Technicians A and B are correct. Visual inspection is the best way to determine the condition of vacuum hoses, as they can often crack or develop leaks over time. Additionally, a vacuum leak can often be heard as a hissing noise, making Technician B's statement correct as well.

Question 20

In the case and duct system the air distribution mode doors may be operated by all of the following Except:
A) Potentiometers
B) Electrically powered motors
C) Cable
D) Vacuum motors

Accepted Answer

Potentiometers are not typically used to operate air distribution mode doors in the case and duct system. Potentiometers are electronic components used for measuring and controlling the electrical potential, typically used in applications such as volume control on amplifiers or as a sensor in various electronic systems. Meanwhile, electrically powered motors, cables, and vacuum motors are all commonly used to operate air distribution mode doors.

Quiz 9: Case and Duct Systems

Technician A says that a liquid antimicrobial deodorizer and disinfectant is used to eliminate odors in duct systems.Technician B says when a musty odor develops the odor causing mold and mildew must be eradicated.Who is correct?

Technician A says a block or ladder diagrams are used to aid in troubleshooting air conditioning duct system faults.Technician Bsays the use of test lights is not recommended for under dash service.Who is correct?

Electronic actuator motors are being discussed.Technician A says a potentiometer provides a door position signal to the programmer.Technician Bsays the programmer grounds one side of the energized motor circuit to stop the door movement.Who is correct?

Technician A says the greatest problem in servicing the case and ducts is lack of tools.Technician B says the greatest problem in servicing the case and ducts is lack of service information.Who is correct?

Name the major components of the air distribution system.

Dual zone duct systems are being discussed.Technician A says the passenger controls only the passenger side temperature door.Technician B says the driver may be in control of the rear passenger compartment temperature on some systems.Who is correct?

It is necessary to drain the engine coolant before replacing

When should the cabin air filter be replaced if the vehicle is operated in dusty or high pollution conditions?

Technician A says a bi-directional mode door actuator may control the mode doors.Technician Bsays a positive pressure is usually maintained within the passenger compartment.Who is correct?

An inoperative vacuum motor could be caused by all of the following,EXCEPT:

Mode door adjustments are being discussed.Technician A says the vacuum motor can be adjusted for motor stroke.Technician B says a cable can be adjusted for full movement of the door.Who is correct?

Technician A says a check valve allows flow in one direction only.Technician B says a check valve blocks flow in one direction only.Who is correct?

Technician Asays the heater control valve is found in-line on the heater hose of most vehicles.Technician Bsays the evaporator may be found inside the engine compartment on some vehicles.Who is correct?

The BILEVEL mode is being discussed.Technician A says air may be directed to the panel and floor in the cooling mode.Technician B says air may be directed to the panel and floor in the heating mode.Who is correct?

Technician A says debris in the fresh air intake can contaminate the refrigerant.Technician Bsays cleaning the fresh air inlet should be part of a periodic preventative maintenance schedule.Who is correct?

In the MAX cooling position the main source of air is from:

What is the sytem called that allows for seperate dirver and front passenger temperature control?

Rear heat/cool systems are being discussed.Technician A says this system has its controls in parallel with the front controls.Technician B says some units have the temperature selected by the front controls.Who is correct?

Technician A says the best way to determine the condition of vacuum hoses is by visual inspection.Technician B says a vacuum leak can often be heard.Who is correct?

In the case and duct system the air distribution mode doors may be operated by all of the following Except: