How Do You Diagnose Auto A/C Expansion Valve Probe?
When liquid refrigerant is forced through a restricted opening, it changes from a liquid to a gas. This change of state causes the refrigerant to become cold, and as it passes through the system, it absorbs heat from the passenger compartment. The vehicle’s air-conditioning relies on this change of state to operate, and the expansion valve provides the restriction used to control the volume and pressure flowing through the system. Diagnoses of expansion valve malfunctions are done with an A/C gauge set. Attach the gauges to the A/C system by locating the low-pressure and high-pressure service ports. The low-pressure port can be found on the low side line between the accumulator (sometimes on the accumulator) and the compressor. The accumulator is the cylindrical part attached to the system near the passenger side of the firewall. The high-pressure port is located on the high side line between the condenser and evaporator. The condenser is the radiator-like part located in the front of
