Ford Repair: 98 Ford Escort A/C, c lines, ford escort

Question
I have a 98 Ford Escort and the A/C recently stopped working. I have taken it to two mechanics and they told me that the part of ECU that controls it is no good. They have tried to find the part but cannot seem to so I am looking on my own. I thought he meant just the relay that controls the compressor was bad but he said it is the whole control unit.Can you help me determine exactly what part that I need? The name of it or some kind of way I can call junk yards and identify the part? I appreciate any help you can give me!!

Answer
you shouldn't need anything related to the e.c.u.- assuming your system is full and the relay is fine. the only thing that controls the a/c are the switches on the car or the low pressure cut out switch ( very common on that year ) it is located in one of the a/c lines a connector with two wires going to it