ASE G1 Domain 7: Heating, Ventilation, and Air Conditioning Welcome to your ASE G1 Domain 7: Heating, Ventilation, and Air Conditioning 1. ASE G1: Heating, Ventilation, and Air Conditioning When diagnosing an A/C system that is not cooling properly, the technician finds that the compressor clutch engages, but the low-side pressure is high and the high-side pressure is low. This could indicate: A. An overcharged system B. A restriction in the high side of the system C. A faulty compressor D. A leaking evaporator None 2. ASE G1: Heating, Ventilation, and Air Conditioning A vehicle's HVAC system emits a musty odor when the A/C is first turned on. The most likely cause of the odor is: A. A dirty cabin air filter B. Mold or mildew in the evaporator case C. An overcharged A/C system D. A refrigerant leak at the heater core None 3. ASE G1: Heating, Ventilation, and Air Conditioning The A/C system is not producing cold air, and the compressor is not engaging. A proper diagnostic step is to: A. Refill the system with refrigerant without checking for leaks B. Bypass the low-pressure switch to test the compressor C. Check the system pressures with A/C gauges D. Immediately replace the A/C compressor None 4. ASE G1: Heating, Ventilation, and Air Conditioning A technician finds that the A/C system's high-pressure cut-off switch has tripped. The FIRST thing they should check is: A. The amount of refrigerant in the system B. The condition of the condenser fins C. The operation of the cooling fans D. The high-pressure line for kinks or damage None 5. ASE G1: Heating, Ventilation, and Air Conditioning During an A/C system performance test, the center vent temperature is higher than specifications with the system set to max cool. The system's refrigerant charge level should be: A. Checked with a recovery/recycling machine B. Assumed correct if the sight glass shows a full charge C. Topped off with refrigerant before other tests D. Evaluated by adding a dye and looking for leaks None 6. ASE G1: Heating, Ventilation, and Air Conditioning The HVAC control head is automatically switching modes from panel vents to defrost during heavy acceleration. This is MOST likely caused by: A. A vacuum leak in the supply line to the control head B. A stuck open thermostat C. A malfunctioning blend door actuator D. An electrical short in the mode selection switch None 7. ASE G1: Heating, Ventilation, and Air Conditioning When the A/C system is turned on, there is a loud noise from the compressor area, and the belt is observed to be slipping. The MOST likely cause is: A. A seized A/C compressor pulley bearing B. A misaligned drive belt C. An undercharged A/C system D. A defective belt tensioner None 8. ASE G1: Heating, Ventilation, and Air Conditioning If the A/C system exhibits poor cooling performance and the sight glass is showing a stream of bubbles at idle, which of the following could be the cause? A. The system is overcharged with refrigerant B. There is air contamination in the system C. The system is low on refrigerant D. The compressor clutch is slipping None 9. ASE G1: Heating, Ventilation, and Air Conditioning A technician is diagnosing an HVAC issue where the heater does not provide sufficient warmth. After verifying proper coolant level and thermostat operation, the NEXT step should be to: A. Replace the heater core B. Flush the cooling system C. Check for proper operation of the heater control valve D. Inspect the blend door operation None 10. ASE G1: Heating, Ventilation, and Air Conditioning When a vehicle's interior smells like antifreeze and the windows fog up when the heater is turned on, this is typically indicative of: A. A clogged cabin air filter B. A leaking heater core C. An overfilled cooling system D. Inadequate coolant level None 1 out of 10 Time is Up! Time's up
