I'm installing a thermostat, but I don't appear to have a C wire. My old thermostat had R/RH,Y,G,and W. It's an AC system that was setup before I got here. The actual AC unit is a long way away and inaccessible because of how the community was built.
I never use my heater and when I measured the voltage, it was 24V (the same as C), so can I use that instead? I read that you can use the fan wire, but I turn my fan to 'ON' at night. I thought if I never use my heater, why not use that? Or am I missing something.
I also have a random blue wire bundled behind my wall, but it didn't power on my thermostat. It read 13V in my multimeter.