Free Car Air Conditioning Repair Question and Answers

Question 1

Which of the following circumstances is most likely to result in a car overheating?

Accepted Answer

Clogged radiator

Answer

A clogged radiator is one of the most common and critical causes of a car overheating. The radiator's primary function is to dissipate heat from the engine coolant. If its internal passages become blocked by debris, rust, or corrosion, the coolant flow is severely restricted, preventing effective heat exchange and causing the engine temperature to rise dangerously, leading to overheating.

Question 2

According to Technician A, when the condenser airflow is restricted, both the high and low lines are under high pressure. When the pressure is low on both the high and low sides, according to technician B, this is a sign of low refrigerant. Who is correct?

Accepted Answer

Both Technician A and B

Answer

Technician A is correct because restricted condenser airflow prevents the system from dissipating heat effectively, causing refrigerant to remain in a high-pressure, high-temperature state throughout, leading to high readings on both gauges. Technician B is also correct; a low refrigerant charge means there isn't enough fluid to build proper pressure, resulting in low pressure readings on both the high and low sides of the system. Both scenarios describe distinct, valid diagnostic indicators in AC systems.

Question 3

The following facts about an air conditioning performance test are all true, EXCEPT for

Accepted Answer

To avoid outside odor, operate AC System in RECIRC rather than FRESH mode

Answer

The question asks for the statement that is NOT true. Operating the AC system in RECIRC (recirculation) mode *does* help avoid outside odors by closing the fresh air intake and recirculating cabin air. Therefore, this statement is actually true, making it the incorrect answer for an 'EXCEPT' question. The other options correctly describe common AC system issues or symptoms.

Question 4

The engine may run excessively cold, according to Technician A, if the thermostat is broken. The thermostat can generate a pinging or pounding noise if it is jammed closed, according to technician B. Who is correct?

Accepted Answer

Both Technician A and B

Answer

Technician A is correct because a thermostat stuck open will allow coolant to continuously flow through the radiator, preventing the engine from reaching its optimal operating temperature and causing it to run excessively cold. Technician B is also correct; a thermostat jammed closed will restrict coolant flow, leading to severe engine overheating and potential pinging or pounding noises from boiling coolant and pressure buildup. Both technicians accurately describe potential thermostat malfunctions and their symptoms.

Question 5

The technician observes that the compressor output is warm when testing the performance of the air conditioner. This is a typical condition, according to technician A. The air conditioning system, according to technician B, is overcharged. Who is correct?

Accepted Answer

Technician A only

Answer

Technician A is correct because the compressor's function is to compress low-pressure, low-temperature gaseous refrigerant into high-pressure, high-temperature gas. This compression process inherently generates heat, making the compressor output naturally warm or hot during normal operation. Therefore, a warm compressor output is a typical condition and not indicative of an overcharged system.

Air Conditioning Repair Practice Test

Air Conditioning Repair Practice Test

Free Car Air Conditioning Repair Question and Answers