ASE A7 Heating Air Conditioning Questions and Answers with complete solution

A CCOT system has a high high side. Technician A says to suspect the thermostatic expansion valve. Technician B says this system contains an orifice tube. Who is correct? TECH B is correct. A clogged orifice tube will result in high high side pressure. It can become clogged with contaminants, debris from a damaged compressor, or a broken desiccant bag releasing desiccant into the refrigerant. A vehicle's air conditioning performance is reduced at low speeds and stop lights, but cools at highway speeds. Which of these is MOST likely the cause of this condition? A. A low refrigerant charge. B. A missing fan shroud. C. A normal condition. D. A faulty compressor clutch relay. Answer B is correct. A properly fitting and fastened fan shroud is vital for good A/C and engine performance. Many of these shrouds and dams create a low pressure area behind the radiator and condenser. Loose or missing shrouds will be especially noticeable as the vehicle slows and ram air is reduced