I am thinking about a wifi thermostat that needs a C wire. I read about converting my G wire to a C wire and then jumping the G and Y at the furnace. This is supposed to work the fan with the A/C, and since the furnace controls the fan anyway, it shouldn't be a problem. My 2 questions: Is this a workable solution? I have a G, W, Y and R wire setup. I have some bell wire (from a garage door button laying around, 18-guage). Is that sufficient for the jump?