I've read many posts on this, and believe I know what to do, but want to make sure. My furnace (a Lennox G14 Series) does not have a C terminal which needs to be connected to the C terminal in my new wifi thermostat. In the attached picture of the terminal strip in the furnace, the red wire on the T terminal and the white wire on the Y terminal go to the air conditioner. The other 4 wires go to the thermostat. I've measure across the R and T terminals and get 28vac. Based on this I believe I can use the T terminal for the C connection…is that right?
Eventually I'll run a 5 wire cable but for now I plan on stealing the green wire to make the C connection if I can use the T terminal.
UPDATE: I've added the wiring diagram from inside the furnace.