What is suggested if both low and high-side pressures are low during an A/C performance test?

When both the low and high-side pressures are low during an A/C performance test, the most indicative action is to add refrigerant. Low pressures in both the low and high sides suggest that there is insufficient refrigerant circulating through the system. The refrigerant is essential for the heat exchange process, and without an adequate amount, the system cannot function properly.

In a properly charged A/C system, the low-side pressure typically indicates the suction pressure while the high-side pressure indicates the discharge pressure. When both readings are low, it typically means that the system is not able to achieve the necessary pressure differential for effective cooling.

Adding refrigerant helps restore the balance of the fluid within the system, ensuring that the compressor can create the correct pressure difference needed to circulate the refrigerant effectively. This action is also an essential part of routine maintenance and can help prevent further system damage that might occur from continued operation under low refrigerant conditions.