Exam 9: Case and Duct Systems

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?

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?

Even in the MAX A/C mode,some systems provide for up to 50 percent fresh air.

If a musty odor develops and becomes very pronounced when the HVAC system is first turned on,the case should be washed out with a garden hose.

Under normal operation,most of the moisture that may build up in the evaporator case will drain out of the case drain.

Technician A says a semiautomatic temperature control (SATC)system is operated by engine vacuum.Technician B says an automatic temperature control (ATC)system is operated by a digital microprocessor.Who is correct?

The blower can be installed upstream or downstream of the other components.

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?

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?

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?

How may a blend door be controlled?

It is necessary to drain the engine coolant before replacing

How does the blend door create the desired in-vehicle temperature?

Why do some systems develop a musty odor?

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?

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

During normal air conditioning system operation,system mode doors are

Why is it desirable to provide a slightly positive in-vehicle pressure?

The independent case is used on compact and small cars.

Why may the air conditioning compressor be on in the defrost (DEF)position?