2001 379 Pete A/C issue

I am guessing here....temp sensor is a mercury fill switch. It's connected to the blower motor so that when you turn on and off the blower motor, it turns off the sensor/switch. The switch itself will open and close as the mercury expands and contracts depending on the cab temperature. When it is closed, it will send current to engage the ac compressor clutch. So no doubt it's important to the whole system. I think temp sensors can come and go working. I had the same problem in my truck and it was the temp sensor. The PCC looks like nothing much more than a link between the temp control and actuator, even though the University of Google calls it a microprocessor controller.