[Chester Stone]

I am so sorry, but I think I have wasted a lot of your time since I have been looking at this incorrectly. I looks like there were two problems that got me confused. The original problem is that nothing worked with the thermostat set to low. With the lines going to the compressors reversed, that problem went away for some unknown reason. Then I got confused between the leads to the compressors and the connectors. I was checking the amperage at the connectors which changed when the wires were reversed. Thus the low 4 amps moved from #1 "connector" to #2 when compressor wires were reversed. Duh! It's the compressor I am switching not the power source. Thus Richard is right, a compressor system problem not the board. Probably low on gas, but testing the system will tell.

As to unconnected commons, this is logical since the two compressors are on different 110 circuits at the breaker box.

Again, sorry.