Pressure cut out switch is mounted on the TX valve, next to the washer bottle. It is a hi and low pressure switch. If you have no gas in the system, the switch will cut the power supply to the compressor. Unplug and bridge the 2 wires then check for power to the compressor. The ECU controls the power to the pressure switch depending on things like evaporator temp etc. My guess is the system has lost its gas. On an EL there are a few common spots that leak, condensor, TX valve o rings, evaporator and even the comprressor front seal. At work I use nitrogen to pressure check A/C systems, works well.