Wow that person who wrote that ticket out needs to do a more professional job. Almost everything wrote out is miss spelled. I am not familiar with that company.
That’s mainly controls the fan operation. Problems with it usually makes the fan come on when it’s not needed. The system still has everything else mentioned. As long as the fans coming on while idling to lower a/c pressure, I doubt it’s the problem. The A/C high pressure switch over rides it anyway, as long as it’s working. It basically says while idling with a/c off, unplug pressure switch on dryer, and fan should come on. Jump wires on plug, fan should go off. If it’s idling, and fans not coming on, and pressure switch is good, A/C compressor will shut down from high pressure, running down the road though, a/c would probably work fine, since the condensors getting cooled. Since the pressure switch over rides the EDM. I doubt it’s the problem. More likely as his friend suggested, a chafed wire, or a bad terminal connection somewhere. I’ve had to replace quite a few Connections on mine. At compressor, at temp control probe, blower motors, blower switches, a loose plug connection, somewhere a plug connector causing intermittent operation of the compressor would be my guess. Assuming the compressors not running when a/c quits working. Somethings intermittently causing a open circuit, or a short to ground. I don’t know much about electrical, past a visual inspection and use of a test light. Most of the switches are constantly hot, and switched through the ground. A break or short to ground on the hot supply wire coming in, or a break in the ground wire going out of any switch causes problems, as does a bad terminal connection. Since his compressor isn’t working consistently, it’s probably a wire connection or chafed wire, or broken wire inside sheathing that can’t be seen, often happens if wire is near a heat source, or vibration source. Near the compressor.
Had a western star that went shop to shop by the driver, he was told they could fix it and just replaced parts - recharged the system or removed freon. A few shops later, I told the driver to take it to a freightliner dealer. the shop manager got it in two days later, the a/c guy first fixed the hacks that the shops did to make it sort of run, then he replaced one part - the ambient temp sensor. Fixed.
Truck is arriving monday to go to local shop who will try to get it fixed on factory harness , if not - next step will be to bring to the other local shop to do old school set up . If anyone have better idea or suggestions i will be happy to deliver the truck anywhere for repairs .