Anyone know what the 7.5V wire connected to a Duotherm analog thermostat is for? I just replaced my analog thermostat with a digital on and didn't use this wire. Just wondering what it is for. My furnace and ac seems to work ok, but its really too cold to tell if the ac is working.
2000 Ford F350 7.3L PSD
2007 Forest River Wildcat 29RLBS