put the thermostat back in the system and then go on the roof and pull the cover both units, You will see a RJ connect phone type . Unplug check for clean, use a tooth brush, plug back in and the do the other one. Try it now, and post back. Doug might ring in later, He works them more than I do. If this does not work then do a reset on the thermostat, might just do it first then if not working , then climb on top. Will get you a link on how to reset the thermostat in a sec.
http://bryantrv.com/docs.html
download for the number of button 4/5 maybe thermostat