A/C Condenser and Line Restrictions
A restricted A/C line or component results in a change or drop in pressure at that point. Because of the close relationship between pressure and temperature, the temperature also drops. These performance-robbing restrictions are far more common on the high side of the system. Even a small restriction greatly affects flow in these smaller liquid lines.
An automotive condenser is located in front of the radiator. It can be struck by road debris, resulting in kinks and possible leaks.
Because of the sudden temperature change, aiming an infrared thermometer at the suspected location is a great way to diagnose this condition.
A kink or restriction in the condenser causes a temperature difference at that point. The area just before the kink is hotter (possibly scorching) than the point after the restriction. The line after the restriction is cooler and probably frozen. Suspect a restriction to flow whenever a frosty point forms on an A/C line or component.