A/C Final

Where is the ambient temperature sensor usually mounted?

In Front of the Radiator

Which sensor might use an aspirator tube?

Inside vehicle temperature

A refrigerant leak can be detected by ________.

Looking for oily areas (visual inspection) Using an electronic leak detector Using a soap solution and looking for bubbles

What could be wrong if the A/C compressor clutch cycles on and off rapidly?

Low refrigerant charge

The ________ door is used to select air discharge location, such as floor, vent, or defrost.

Mode

A five-wire actuator uses two wires to power the ________ and three wires for a ________.

Motor; potentiometer

A faulty A/C system has a high low-side pressure and a high high-side pressure. Technician A says that the system is probably low on refrigerant. Technician B says that the system has a bad thermostatic switch. Which technician is correct?

Neither

What is the color of the plastic conduit used over high- voltage wiring to an electric A/C compressor?

Orange

Electrically powered A/C compressors should use what type of refrigerant oil?

POE

The basic designs of AC compressors include ________, ________, and ________.

Piston, vane, and scroll

A feedback potentiometer is used to ________.

Provide feedback to the controller as to the location of a door or valve

The air inlet door is set to ________ when "MAX A/C" is selected.

Recirculate air

Most piston compressors use what type of valves?

Reed

The HVAC control module uses ________ to control high current loads in the A/C system.

Relays

A compressor belt tensioner is bouncing rapidly with the engine running. What should the technician do?

Remove the tensioner and lubricate the dampener

The low-side pressure is low and the high-side pressure is higher than normal. What is the most likely cause?

Restriction on the high-side line

If a wire repair, such as that made under the hood or under the vehicle, is exposed to the elements, which type of repair should be used?

Solder and adhesive-lined heat shrink or crimp-and-seal connectors

Technician A says that PTC heaters can be built into a conventional heater core assembly. Technician B says that a PTC heater's electrical resistance will decrease as its temperature increases. Which technician is correct?

Tech A Only

An AC system is being checked for proper cooling. Technician A says to turn on the AC system and operate the engine at 1500 to 2000 RPM for 5 to 10 minutes before checking the outlet temperature. Technician B says that the temperature can be checked as soon as 1500 RPM is reached. Which technician is correct?

Tech A only

Both high-side pressures and low-side pressures are low with the engine running and the selector set to the air conditioning position. Technician A says that the system is undercharged. Technician B says the cooling fan could be inoperative. Which technician is correct?

Tech A only

The HEV electric compressor operates at a voltage of up to ________ volts.

230

AC vent temperature at the center outlet should be

35°F-45°F (2°C-7°C)

The pressure relief valve on a 134a A/C system will open at about ________ PSI

400

When testing a relay using an ohmmeter, which two terminals should be touched to measure the coil resistance?

86 and 85

What is a "reheat" system?

A system that cools the air through the evaporator then heats the air though airflow though the heater core

Most A/C performance tests include

All of these

What is the purpose of the clutch on an A/C compressor?

Allows the compressor to be turned on and off

What is used to help keep the passenger compartment warm during idle-stop (start-stop) operation?

An auxiliary electric water pump

Technician A says that the HVAC doors in an automatic system may be cable operated. Technician B says that the HVAC doors in an automatic system may be operated by electric servos. Which technician is correct?

B only

The AC compressor clutch is being checked to see if it is engaged. Technician A says that if the drive belt is moving, the compressor is working. Technician B says that the compressor will often "click" when it is energized and de- energized. Which technician is correct?

B only

Which of these ATC output devices provides a feedback signal to the electronic control module (ECM)?

Blend door actuator

Technician A says that a good relay should measure between 60 and 100 ohms across the coil terminals. Technician B says that OL should be displayed on an ohmmeter when touching terminals 30 and 87. Which technician is correct?

Botch techs

Technician A says that module communications networks are used to reduce the number of wires in a vehicle. Technician B says that a communications network is used to share data from sensors, which can be used by many different modules. Which technician is correct?

Both

In a schematic, a wire is labeled "0.8 BLK/WHT." This wire is ________.

Both 0.8 mm diameter and Black with a White stripe

A compressor speed (belt lock) sensor is used by the HVAC ECM to ________.

Both Prevent a locked-up compressor from destroying the engine drive belt and Determine if the compressor is running by comparing the compressor and engine speed signals

Technician A says that HEV compressors may be both electrically and belt driven. Technician B says that scroll type A/C compressors contain an oscillating scroll and stationary scroll to pressurize the refrigerant. Which technician is correct?

Both Techs

Two technicians are discussing variable displacement piston compressors. Technician A says that the wobble plate is moved to the high-angle position for maximum output when the cooling load is high. Technician B says that the wobble-plate angle is controlled by the pressure in the crankcase of the compressor. Which technician is correct?

Both techs

The compressor is working if the ________ of the compressor clutch is rotating.

Center

Cabin filters may be treated with ________ to help reduce odors.

Charcoal

While diagnosing an A/C concern the scan tool reads "Inside Air Temp = 90°" and "Ambient Temp = -38°". Shop temperature is 87°. What should the technician do?

Check the ambient sensor and connections

Water discovered on the floor on the passenger side of a vehicle is an indication of what problem?

Clogged evaporator drain

A complete circuit that is continuous from source through loads and back to ground has ________.

Continuity

High resistance in an electrical circuit can cause

Dim lights Slow motor operation Clicking of relays or solenoids

A clutchless damper drive is used with what type of AC compressor?

Electronic-controlled, variable displacement compressor

What is the control device used inside an electric A/C control actuator?

Eletric motor

Most A/C systems first pass the air through the ________ as it enters the vehicle.

Evaporator

In a system that is operating correctly, the lines and hoses on the high side should be

Hot to the touch

Technician A says that as the clutch drive hub is replaced, the air gap should be checked at three different places. Technician B says that the air gap is not important as long as the clutch coil resistance (in ohms) is correct. Which technician is correct?

Tech A only

Technician A says that oily residue on a fitting or hose can indicate a refrigerant leak. Technician B says that this residue is normal around most A/C fittings. Which technician is correct?

Tech A only

Two technicians are discussing compressor replacement. Technician A says that the new compressor already has the proper type and amount of oil installed. Technician B says that the included directions should be followed before installing the new compressor. Which technician is correct?

Tech b only

The door used to control interior temperature is called the ________ door.

Tempature-blend

A dual-zone A/C system allows for different ________ for the driver and passenger.

Temperatures

How is the AC compressor lubricated in an R-134a system?

The oil moves through the system simply with the movement of the refrigerant

An airflow (blend) door may be broken if

There is a clicking noise from the actuator motor assembly as it tries to move a broken door, Outlet temperature can change from hot to cold or from cold to hot at any time especially when cornering There is a change in the temperature when the fan speed is changed

Most recent HVAC actuators are recalibrated after replacement by

Using a scan tool or allow it to self-learn after being installed

In an operating A/C system, the outlet line from the evaporator should be

cool

Which type of DMM can measure current when clamped around a conductor?

inductive