I have recently added a second roof air, as mine only had one when purchased. I have found and connected to all the appropriate wiring, with exception of the 12 volt that supplies the thermostat. Why? Because I can't find it and it is nowhere in any wiring diagrams I have been able to find. Which is not many. There is a orange and orange white pair in ceiling. I have tested this line and it doesn't have any power to it. Any suggestions? Your help would be greatly appreciated. Thanks.