After a bit of research I discovered my thermostat was bad. It was not signaling the compressor to start. I replaced it and now I have a working refrigerator. Thank you to everyone for your assistance last month.
Another question regarding the refrigerator (fresh food) side of this 2 compressor Sub Zero Model 532:
Is the copper line that returns the R-12 to the compressor after it leaves the evaporator coil supposed to be frosty? The 12 inches of un-insulated copper line that enters the compressor has a visible frost on it when the compressor is running.