Jumping wires
 

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?

You will then not be able to run the fan on constant if you would like to. You can get a wireless stat or see venstar add-a-wire device.