My Monty is prewired for a second A/C also. The thermostat has two zones. I only use zone 1 now because of only having the one A/C. Zone 2 would be used with the second A/C. Yours should have the same setup. But, I'm sure other's will come along who are more knowledgable than I am about such things.
The comfort control center is quite a gadget. It controls multiple ACs and furnaces, it can stagger AC operations for limited power supplies, and it can even start a generator.
Unfortunately, I do not believe Keystone ties in the 2nd AC as part of the 2nd AC prep. It requires a Cat5 cable from the thermostat. We ordered the 2nd AC and I do not see any connection. The 2nd AC is operated manually from the controls provided on the AC.
Can it be changed to operate from the thermostat? I don't know.
We had the second AC installed prior to pick up....Texas just gets TOO hot without it!!! It works independantly from the Living Room thermostat...which they later replaced for us free of charge. We had constant problems with the remote control for it. Our dealer said the 2007 were not going to have them anymore.....guess we were not the only ones challenged!!!!
I do not see how the CCC can run another zone without a temp sensor to register the temp to cut the unit on and off. I think Brad is right on with the Cat 5 cable requirement; it probably goes to a zone sensor for temp readings. I had zones in my last stick home, worked great, bur required a lot of wiring and sensors to a main control in order to operate dampers, blower, compressor, et.