I am one of the lucky ones that has his HVAC in the craw space above his house (please note scarcasm). It is a b%#*% to get up there and after finally finding where the wires from my 3M-50 goes to, it saddnes me to see there no C output. Now, I know that if my HVAC has power it has Common Power, but I don't know where to get it from. I have an extra blue wire that is unplugged at both sides, but I am out of ideas of where to connect it to.
There are no capped wires and there is no output for "C". I have dedicated outputs for "G", "Y" ,I think the next one is "W", another random green wire, and "R".