ASE A7 HEATING AND AIR
CONDITIONING PRACTICE
EXAM COMPLETE 60
QUESTIONS
Question 1: During an A/C performance test the technician wants results that can be compared with service information. Which condition should be established before judging system pressures and outlet temperature?
Choices:
1) Run the engine at any speed that keeps the compressor engaged 2) Set the blower to the lowest speed and close all vents 3) Add refrigerant until the low-side pressure reaches 35 psi 4) Follow the manufacturer procedure for ambient temperature, engine speed, blower setting, and door position Correct Answer: Follow the manufacturer procedure for ambient temperature, engine speed, blower setting, and door position Explanation: A meaningful performance test must be run under the vehicle manufacturer's speci�ed test conditions. Ambient temperature, engine speed, blower setting, recirculation or fresh-air mode, and vent selection can all a�ect pressures and outlet temperature.Page 1
Question 2: A manual HVAC blower operates only on HIGH speed. The motor itself
runs normally on HIGH. Which component is MOST likely faulty?
Choices:
1) The compressor clutch bearing 2) The thermostat 3) The blower resistor assembly or its lower-speed circuit 4) The receiver/drier
Correct Answer: The blower resistor assembly or its lower-speed circuit
Explanation: Traditional resistor-controlled blowers often bypass the resistor on HIGH. If only HIGH works, an open resistor element, thermal fuse, connector, or related lower-speed circuit is a common cause.Question 3: The A/C clutch does not engage. The clutch coil has battery voltage and a good ground when commanded ON, but an ohmmeter shows in�nite resistance through the coil. What is the fault?
Choices:
1) An open clutch coil 2) A shorted evaporator temperature sensor 3) A restricted condenser 4) A weak thermostat spring
Correct Answer: An open clutch coil
Explanation: In�nite resistance through the clutch coil indicates an open winding. With proper power and ground present, the clutch coil or clutch assembly should be serviced as speci�ed.Page 2
Question 4: A vehicle cools normally at highway speed but the vent temperature
rises while idling in tra�c. High-side pressure also increases sharply at idle. Which problem is MOST likely?
Choices:
1) A stuck-open thermostat 2) A restricted cabin air �lter 3) An overactive evaporator temperature sensor 4) Insu�cient condenser air�ow
Correct Answer: Insu�cient condenser air�ow
Explanation: Condenser heat rejection depends heavily on air�ow at low vehicle speed. An inoperative condenser/radiator fan or blocked air�ow can cause high head pressure and poor cooling at idle while road speed temporarily masks the problem.
Question 5: The blower is commanded to HIGH. Battery voltage is present at the
blower power terminal and ground-side voltage drop is only 0.1 volt, but the motor does not turn. What is the MOST likely fault?
Choices:
1) A failed blower motor 2) A restricted expansion valve 3) A contaminated refrigerant charge 4) A leaking heater core
Correct Answer: A failed blower motor
Explanation: The motor has adequate power and a good ground yet does not operate. That points to an internal blower-motor failure rather than a refrigeration or coolant problem.Page 3