I've got my new Totaline Wireless stat installed and working on my gas furnace. My old stat, a Honeywell, only had 3 wires going to it (W,G,R). When I first hooked up the new stat and ran the fan I had the problem with the fan cycling on and off every few seconds. The lights on the new stat would also dim. If I tried to turn the heat on the furnace would turn off and the stat would lose power. From the manual and what I read online it sounded like a 270 ohm 10 watt resistor between 2 of the terminals on the furnace would fix it. It did not. I removed the resistor and hooked up the, previously unused, C terminal wire to the new stat. This fixed the problem and it works fine now. I'm am curious if this was the correct thing to do and why this fixed the problem. Any thoughts?