Hybrid-Technology Principles and Consumer Comm. of Automotive HVAC (AD12-156-2.0.1) UNIT 4 QUIZ STUDY GUIDE

While diagnosing the condenser cooling fan, a _________________ is used to check battery voltage.

DMM

A thermostatic cycling switch is used to prevent ______________ freeze up.

Evaporator

A clamping diode allows voltage spikes to return to electric modules and components on the vehicle.

False

A high pressure cut out switch is used to vent refrigerants to the atmosphere

False

Condensers are used in an A/C system to change a liquid to a vapor.

False

Pressure cycling switches are found only on the high side of an A/C system.

False

Refrigerant enters the condenser as a high pressure low temperature vapor.

False

Technician B says when checking a field coil for continuity, OL indicates the circuit is shorted to ground.

False

Technician L says that a fin tool is used to diagnose the compressor clutch

False

Technician O states that some compressor clutches use pressure cycling switches to automatically adjust the air gap.

False

Technician Q says that when diagnosing an A/C system with a scan tool you should verify ambient temperature is below 40f.

False

Technician S says that you can resolve evaporator concerns by removing the fixed orifice tube.

False

Technician v states that the spanner wrenches are never needed during compressor clutch service.

False

In general, you may resolve evaporator concerns by replacing the evaporator when it has a ____________ or __________.

Leak or clog

When installing the evaporator, you must align the upper plenum onto the ____________.

Lower plenum

How is the electro-magnetic clutch controlled in a switch controlled system?

Pressure Switch

Some compressors require the use of a clutch hub installer to adjust air gaps between the compressor clutch hub and the compressor ____________.

Pully

On what two lines is an H-valve located?

Suction line and the liquid line

In a switch controlled A/C system a ___________ controls the compressor clutch operations.

Switch

The ____________ may be in series with the compressor clutch coil.

Switch

Air conditioned equipped vehicles use a mechanical fan or an electrical fan to remove heat from the condenser.

True

On air conditioning systems equipped with a pressure-cycling switch, a compressor that rapidly cycles on and off is an indication of low refrigerant.

True

Some vehicles are equipped with two condenser cooling fans

True

Technician A states that a typical resistance reading for a field coil is 3 to 5 ohms.

True

Technician D says that id the TXV is not operating properly, it can cause poor air condition performance.

True

Technician E says that in some vehicles, the pressure cycling switch directly controls the compressor clutch.

True

Technician F says that some vehicles use a control module to manage the compressor clutch.

True

Technician G says that visual inspection of a compressor using a clutch involves checking for metallic dust on the pully.

True

Technician H says that you should inspect the wiring harness to the compressor clutch for proper routing, chafing, or breaks.

True

Technician I says that evaporator temperature measurements are useful for resolving TXV concerns.

True

Technician J says that measuring the outlet and inlet temperature differential of the evaporator is helpful in diagnosing a faulty metering device.

True

Technician K says that field coil resistance measurements are needed to diagnose a compressor clutch.

True

Technician M says that manifold gauges can be used to test TXV concerns while the A/C system is running.

True

Technician P states that the compressor clutch air gap can be measured using a feeler gauge.

True

Technician R states you should check engine coolant temperature sensor data and verify that below 255f.

True

Technician T says that the evaporator inlet and outlet temperature can help determine if refrigerant must be added to the A/C system.

True

Technician U says that you could replace the clutch if the compressor is okay.

True

Mold and a musty odor coming from the _____________ could cause a customer concern.

Vent

What must you do when retro-fitting a system from R-12 to R-134a?

prevent cross contamination, and service the valve fitting

Technician C says if a TXV is not operating properly, it can affect high-side and low-side pressure.

true

Technician N says that the TXV's sensing bulb needs to make good contact with the evaporator outlet when diagnosing the TXV.

true