[Chester Stone]

Well, I am out of luck. The white wire in #4 pin is grounded, and so is the blue and large green wires at the thermostat. I checked continuity, but since they are all grounded, there is continuity. I also checked the front thermostat wiring, which runs as it should, and both thermostats are wired the same. Since both rear compressors run at 8 amps when connected to the number 2 compressor connection, I can only conclude that any problems are in the circuit board. I think I will call Flight Systems on Monday to verity that they still rebuild CSC boards. On the internet, I note that the rebuild price has gone up from $85 four years ago to $195. I may switch boards next week before sending it off for repair. Any other thoughts? Again, thanks guys.