I have a Carrier Residential ac unit model 38YCCO36320 using a ait handler model FA4ANF036 for the past 5-7 years now with absolutely no problems. Last month or so, when the cooler weather arrived, I turned off my ac at the thermostat but when the hot weather came back acouple days ago, the ac wouldn't work.. I couldn't get the outside unit to turn on nor the air handler inside even using the "fan" switch on the thermostat. I checked the circuit breakers and they all work and are furnishing power to the lines... I assumed the thermaostat went bad and replaced it but that did not solve my problem.. I don't knoe which on the thermostat wires do what in order to put a jumper on to see if I can get the air handler fan to come on.. Can anybody tell me how to do this ? Tell me which wire in the thermostat does what and how to jump them ? Also, do they carry and electrical charge ? I believe this is where the 24 volts is used to carrying the thermostat's commands to the respective unit to tell it to turn on the compressor or air handler, etc.. And feel that maybe that can possibly be the problem that the converter failed (that produces the 24 volts (is that AC or Dc volts ?) from the 220 AC volts that supplies these units to run.. Can anybody give me any advice.. I am disabled and can't afford a contractor to fix this and my medicine makes me extremely heat sensitive and fatigue... my medicals bills have me completely ruined financially so I will have to solve this myself.. I just can't believe it was fine a month ago and now it won't even work.. Weird!! Thanks for any help..