The control board has relays that'll turn the blower motor on. The only difference is now, you wont be able to turn on the blower motor when setting the fan to ON from AUTO
If you're thermostat wire are ONLY 4 wires. Take the Green wire behind the thermostat and put it onto the C terminal, and do the same thing to the furnace control board, take the Green wire off the G terminal and put it onto the C terminal
Typical thermostat wires used are Red to R. White to W. Green to G. Yellow to Y. The Blue wire goes to C terminal on both, thermostat and furnace control board
Mike, C wire isnt required. The C wire is where it keep the battery charged. Aside from that you'll have to charge it every year or so. Which only take about 15 minutes
